Recombinant Staphylococcus aureus UPF0316 protein NWMN_1849 (NWMN_1849)

What is Recombinant Staphylococcus aureus UPF0316 protein NWMN_1849?

Recombinant Staphylococcus aureus UPF0316 protein NWMN_1849 is a full-length protein consisting of 200 amino acids derived from Staphylococcus aureus strain Newman. The protein belongs to the UPF0316 family, where "UPF" designates an uncharacterized protein family, indicating that its precise biological function remains to be fully elucidated. For recombinant expression, it is typically fused to an N-terminal His tag and expressed in prokaryotic systems like E. coli . The protein's complete amino acid sequence has been determined, allowing for structural and functional studies to progress despite its uncharacterized status.

What are the optimal storage conditions for working with recombinant NWMN_1849?

The recommended storage protocol for recombinant NWMN_1849 involves specific conditions to maintain protein stability and activity. The protein is typically supplied as a lyophilized powder and should be stored at -20°C/-80°C upon receipt. For long-term storage, aliquoting is necessary to avoid repeated freeze-thaw cycles that can damage protein structure. The recommended storage buffer is Tris/PBS-based with 6% Trehalose at pH 8.0 .

For reconstitution, the protein should be centrifuged briefly before opening to bring contents to the bottom. Reconstitute in deionized sterile water to a concentration of 0.1-1.0 mg/mL. For extended storage of the reconstituted protein, adding glycerol to a final concentration of 5-50% is recommended, with 50% being the default. Working aliquots can be stored at 4°C for up to one week . These precise storage conditions are essential for maintaining protein integrity in experimental workflows.

What expression systems are optimal for producing Recombinant NWMN_1849?

While E. coli is the most commonly used expression system for NWMN_1849, researchers have several options depending on their experimental requirements:

When choosing an expression system, researchers should consider the downstream applications and the specific requirements for protein folding and modifications . For basic characterization and initial studies, E. coli remains the most efficient system, while more complex functional assays might benefit from alternative expression platforms.

What challenges might arise during NWMN_1849 expression and how can they be addressed?

Expression of full-length proteins like NWMN_1849 can present several challenges:

• Hydrophobicity issues: Analysis of the NWMN_1849 sequence reveals hydrophobic regions that may impede soluble expression. For proteins with high hydrophobicity, consider using solubility tags (e.g., SUMO, MBP) or specialized E. coli strains designed for membrane protein expression .

• Codon optimization: When expressing Staphylococcus aureus proteins in E. coli, codon bias can significantly impact expression efficiency. Codon optimization of the gene sequence for the expression host is recommended to overcome translation bottlenecks caused by rare codons .

• Translation initiation problems: Truncated products may result from improper translation initiation or proteolysis. Using fusion tags at both N- and C-termini can help distinguish full-length proteins from truncated versions. Increasing imidazole concentration during purification can also improve specificity when using His-tag affinity chromatography .

• Protein toxicity: If NWMN_1849 exhibits toxicity to the expression host, consider using tightly regulated inducible promoters or lower growth temperatures to reduce metabolic burden. Leaky expression can be mitigated by using glucose to suppress basal expression in lac-based systems .

Addressing these challenges requires systematic optimization of expression conditions, including temperature, inducer concentration, and incubation time. Pilot expression studies with small-scale cultures are recommended before scaling up production .

How should experiments be designed to investigate potential functions of NWMN_1849?

Investigating an uncharacterized protein like NWMN_1849 requires a systematic, multi-faceted approach:

• Start with bioinformatic analysis: Begin by comparing NWMN_1849 with characterized proteins using tools like BLAST, Pfam, and structural prediction algorithms. This can provide initial hypotheses about function based on sequence or structural similarities.

• Design a sequential experimental plan: Follow a logical progression from basic to complex experiments:

  • Biochemical characterization (size, oligomeric state, stability)

  • Structural studies (crystallography, NMR, or cryo-EM)

  • Functional assays based on bioinformatic predictions

  • Protein-protein interaction studies

  • Gene knockout/knockdown studies in S. aureus

• Implement proper controls: For each experiment, include both positive and negative controls. For interaction studies, use known interacting proteins as positive controls and unrelated proteins as negative controls .

• Consider experimental power: Calculate the required sample size and number of replicates based on anticipated effect size and desired statistical power. This prevents both underpowered studies that miss true effects and wasteful overpowered studies .

• Use blocking techniques: When studying protein-protein interactions, use blocking designs to reduce variability and increase precision. This is particularly important when working with complex biological systems where many factors can influence results .

A well-designed experimental approach for NWMN_1849 would incorporate elements from successful studies of other UPF proteins while maintaining flexibility to pursue unexpected findings that may emerge .

What controls should be included when studying protein-protein interactions of NWMN_1849?

When investigating protein-protein interactions involving NWMN_1849, rigorous controls are essential for generating reliable and interpretable data:

• Input controls: Always analyze a portion of the initial protein mixture to confirm the presence and quantity of all proteins before interaction assays. This establishes a baseline for comparison .

• Tag-only controls: When using tagged versions of NWMN_1849, include the tag alone (e.g., His-tag only) as a control to identify nonspecific interactions caused by the tag rather than NWMN_1849 itself .

• Irrelevant protein controls: Include an unrelated protein with similar size and properties to NWMN_1849 to distinguish specific from nonspecific interactions. For example, when testing interactions between NWMN_1849 and potential binding partners, include an unrelated bacterial protein with similar characteristics .

• Reciprocal pulldowns: If investigating an interaction between NWMN_1849 and Protein X, perform pulldowns in both directions: using NWMN_1849 as bait to capture Protein X, and using Protein X as bait to capture NWMN_1849. Consistent results from both approaches strengthen evidence for a genuine interaction .

• Binding condition variants: Test interactions under different conditions (salt concentration, pH, temperature) to determine the specificity and robustness of the interaction. True interactions often persist across a range of physiologically relevant conditions .

In GST pulldown experiments, for instance, approximately 10% of input UPF proteins typically bind to GST-RF3, providing a benchmark for interaction strength assessment . This type of quantitative evaluation helps distinguish weak but specific interactions from experimental noise.

How can experimental design be optimized for studying NWMN_1849 in the context of S. aureus pathogenesis?

Studying NWMN_1849 in the context of S. aureus pathogenesis requires careful experimental design considerations:

• Selection of appropriate S. aureus strains: Use both laboratory strains and clinical isolates to ensure comprehensive understanding. The Newman strain, from which NWMN_1849 derives, should be compared with other common reference strains (e.g., USA300, MRSA252) to identify strain-specific effects.

• Genetic manipulation approaches:

  • Generate clean deletion mutants of NWMN_1849 using allelic replacement

  • Create complemented strains to verify phenotypes

  • Consider conditional expression systems for essential genes

  • Implement CRISPR-Cas9 systems for precise genetic manipulation

• Phenotypic characterization pipeline:

• Avoiding experimental bias: Implement randomization in animal studies and blinding in assessment of outcomes. Use blocking designs to account for variability in experimental conditions .

• Protocol optimization: For each assay, conduct pilot experiments to determine optimal conditions. For infection models, carefully define endpoints and sample size based on expected effect sizes .

This systematic approach enables robust assessment of NWMN_1849's role in pathogenesis while minimizing experimental artifacts and maximizing reproducibility .

How does NWMN_1849 relate to other UPF proteins in bacterial systems?

While specific information about NWMN_1849's relationship to other UPF proteins is limited in the search results, insights can be drawn from general UPF protein research:

A methodological approach to explore NWMN_1849's relationships with other UPF proteins would include:

• Phylogenetic analysis: Construct phylogenetic trees of UPF0316 family proteins across bacterial species to identify evolutionary relationships and conserved domains. This can provide insights into potential shared functions.

• Structural comparisons: Use techniques like X-ray crystallography or structural prediction tools to compare NWMN_1849's three-dimensional structure with other UPF proteins. Structural similarities often suggest functional similarities even when sequence homology is limited.

• Functional complementation studies: Express NWMN_1849 in bacterial systems lacking related UPF proteins to assess whether it can complement their functions. This approach has been successful in characterizing relationships between UPF3A and UPF3B in eukaryotic systems .

• Protein-protein interaction network analysis: Identify interaction partners of NWMN_1849 and compare them with known interactors of other UPF proteins to map functional relationships. For example, studies of eukaryotic UPF proteins revealed interactions with release factors (RFs) that provide clues to their functions .

Understanding these relationships could provide valuable insights into bacterial RNA processing and quality control mechanisms, potentially revealing novel targets for antimicrobial development.

What approaches can be used to detect and analyze post-translational modifications of NWMN_1849?

Post-translational modifications (PTMs) can significantly impact protein function and activity. For NWMN_1849, a systematic approach to PTM analysis would include:

• Prediction-based screening: Begin with computational prediction of potential PTM sites using algorithms specific for bacterial proteins. Common bacterial PTMs include phosphorylation, methylation, acetylation, and glycosylation.

• Mass spectrometry-based identification:

  • Use high-resolution LC-MS/MS for unbiased PTM discovery

  • Implement enrichment strategies for specific PTMs (e.g., phosphopeptide enrichment using TiO₂)

  • Compare PTM profiles under different growth conditions to identify regulated modifications

• Site-specific validation: Once potential PTM sites are identified, validate them using:

  • Site-directed mutagenesis to create non-modifiable variants

  • PTM-specific antibodies (when available)

  • Functional assays comparing wild-type and mutant proteins

• Quantitative PTM analysis: For studying dynamics of modifications:

• Functional impact assessment: For each validated PTM, assess its impact on:

  • Protein stability and half-life

  • Subcellular localization

  • Protein-protein interactions

  • Enzymatic activity (if applicable)

This comprehensive approach would provide insights into how NWMN_1849's function might be regulated post-translationally in different environmental contexts, potentially revealing mechanisms of adaptation or virulence regulation in S. aureus.

How should researchers interpret contradictory results regarding NWMN_1849 function?

When faced with contradictory results in NWMN_1849 research, a systematic approach to resolution includes:

• Examine methodological differences: Carefully compare experimental protocols, including:

  • Protein preparation methods (tags, purification approach)

  • Assay conditions (buffer composition, temperature, pH)

  • Detection methods and their sensitivity

  • Statistical approaches and significance thresholds

• Consider biological context: Different experimental systems might reveal different facets of protein function:

  • In vitro vs. in vivo studies

  • Heterologous expression vs. native context

  • Different bacterial strains or growth conditions

  • Acute vs. chronic infection models

• Evaluate experimental design quality: Assess whether contradictions might stem from design limitations :

  • Sample size and statistical power

  • Appropriate controls

  • Blinding and randomization

  • Potential confounding variables

• Implement reconciliation experiments: Design studies specifically to address contradictions:

  • Side-by-side comparisons under standardized conditions

  • Dose-response or time-course experiments that might reveal threshold effects

  • Combination approaches that test multiple variables simultaneously

• Apply Bayesian thinking: Update confidence in hypotheses based on the strength and reproducibility of evidence rather than binary acceptance/rejection of findings .

When reanalyzing experimental results, consider that slight modifications to conditions can significantly impact outcomes. For example, protein interaction studies might benefit from adjusting selection strength: "simulations predict that both experiments would have benefited from slightly weaker selection... which would have enabled a faster exploration of the neighborhood of the wildtype sequence and the occurrence of slightly more deleterious mutations" .

What bioinformatics approaches are most effective for predicting NWMN_1849 function?

Given NWMN_1849's uncharacterized status, bioinformatics approaches offer valuable starting points for functional prediction:

• Sequence-based analysis:

  • Multiple sequence alignment with homologs to identify conserved residues

  • Motif scanning to detect functional domains

  • Transmembrane topology prediction (particularly relevant given the sequence characteristics of NWMN_1849 suggesting membrane association)

  • Signal peptide and subcellular localization prediction

• Structure-based prediction:

  • Ab initio structure prediction using AlphaFold2 or RoseTTAFold

  • Template-based modeling using solved structures of related proteins

  • Structural alignment with functionally characterized proteins

  • Active site and binding pocket identification

• Genomic context analysis:

  • Examination of genomic neighborhood for functionally related genes

  • Operon structure prediction

  • Comparative genomics across Staphylococcus species

  • Co-expression pattern analysis

• Integrated approaches:

• Validation planning: Design experiments to test predictions using:

  • Site-directed mutagenesis of predicted functional residues

  • Domain deletion/swapping to test functional assignments

  • Heterologous expression to test predicted activities

While computational predictions provide valuable hypotheses, experimental validation remains essential. As noted in recent protein structure prediction research: "our computational approach is very efficient and can be applied to thousands of protein families, while the experiments are very expensive in time and resources. Guiding them to increase the success probability may therefore be an impactful strategy" .

How can researchers effectively design experiments to validate or refute computational predictions about NWMN_1849?

Validating computational predictions about NWMN_1849 requires a strategic experimental approach:

• Prioritize predictions based on confidence scores and biological relevance:

  • Focus on predictions with high confidence scores from multiple tools

  • Prioritize predictions relevant to S. aureus biology and pathogenesis

  • Consider the experimental feasibility of validation

• Design a multi-level validation strategy:

• Implement targeted mutagenesis:

  • Create alanine substitutions of predicted critical residues

  • Design domain deletion constructs to test modular function

  • Generate chimeric proteins to test domain function predictions

• Apply orthogonal approaches:

  • Use multiple independent techniques to test each prediction

  • Combine in vitro, in vivo, and in silico approaches

  • Implement genetic and biochemical methods in parallel

• Establish quantitative success criteria before experimentation:

  • Define thresholds for accepting/rejecting predictions

  • Establish statistical requirements (p-values, confidence intervals)

  • Determine required replication levels based on expected effect sizes

• Iterative refinement:

  • Use initial results to refine computational models

  • Develop second-generation predictions incorporating experimental data

  • Create a feedback loop between computation and experimentation

This approach maximizes the efficiency of validation efforts while maintaining scientific rigor. As noted in experimental design literature: "our approach can be used to explore different protocols, such as alternating cycles of strong and weak selection" , suggesting that adaptive experimental strategies are particularly valuable for novel protein characterization.

What role might NWMN_1849 play in S. aureus pathogenesis and antimicrobial resistance?

While direct evidence of NWMN_1849's role in pathogenesis is not explicitly stated in the search results, its investigation as a potential pathogenesis factor is warranted based on several considerations:

• Membrane protein characteristics: Analysis of NWMN_1849's amino acid sequence reveals features consistent with a membrane protein, including hydrophobic segments that may form transmembrane domains . Bacterial membrane proteins often play crucial roles in:

  • Adhesion to host surfaces

  • Nutrient acquisition in the host environment

  • Evasion of host immune responses

  • Antibiotic resistance mechanisms

• Research focus on recombinant production: The emphasis on recombinant production of NWMN_1849 for vaccine development suggests potential immunogenicity and relevance to host-pathogen interactions .

• Methodological approach to investigate pathogenesis roles:

  a) Gene expression analysis: Measure NWMN_1849 expression under conditions mimicking host environments (serum exposure, phagocytosis, biofilm formation) to identify potential regulation patterns associated with virulence.

  b) Mutagenesis studies: Create and characterize NWMN_1849 deletion and complemented strains in:

  • Growth assays under various stresses

  • Biofilm formation models

  • Host cell adhesion and invasion assays

  • Animal infection models

  c) Antimicrobial susceptibility testing: Compare minimum inhibitory concentrations (MICs) of various antibiotics between wild-type and NWMN_1849-mutant strains to identify potential contributions to resistance.

  d) Interaction with host factors: Investigate potential interactions between NWMN_1849 and host immune components or extracellular matrix proteins using techniques such as far-Western blotting or surface plasmon resonance.

Given S. aureus' clinical importance and the challenges of antimicrobial resistance, characterizing proteins like NWMN_1849 may reveal novel therapeutic targets or vaccine candidates. The investigation should follow rigorous experimental design principles to ensure reliable and reproducible results .

How can NWMN_1849 be effectively used in functional genomics approaches to understand S. aureus biology?

NWMN_1849 can serve as a valuable component in functional genomics studies aiming to comprehensively understand S. aureus biology:

• Integration into genomic interaction networks:

  • Perform systematic genetic interaction screens (e.g., synthetic genetic array) with NWMN_1849 deletion to identify genetic relationships

  • Map physical interaction networks using techniques like affinity purification-mass spectrometry

  • Integrate NWMN_1849 into existing S. aureus gene-gene and protein-protein interaction networks

• Transcriptomic analysis approaches:

  • Compare RNA-seq profiles between wild-type and NWMN_1849 mutant strains under various conditions

  • Identify co-expressed genes through correlation network analysis

  • Use conditional expression systems to perform time-resolved expression studies

• Integrated multi-omics studies:

• CRISPR-based functional genomics:

  • Implement CRISPRi for partial knockdown to assess dosage effects

  • Use CRISPR activation to study the effects of NWMN_1849 overexpression

  • Employ multiplexed CRISPR screens to identify synthetic interactions

• Comparative genomics across S. aureus strains:

  • Compare NWMN_1849 sequence, genomic context, and expression across clinical isolates

  • Correlate variations with strain-specific phenotypes (virulence, antibiotic resistance)

  • Identify selective pressures through evolutionary analysis

This multi-faceted approach allows researchers to place NWMN_1849 within the broader context of S. aureus biology, providing insights into both its specific functions and its contributions to bacterial physiology and pathogenesis. As noted in experimental design literature, such comprehensive approaches benefit from careful planning to "optimize experimental design" and "guide experiments to increase the success probability" .

What are the most promising future research directions for understanding NWMN_1849 function?

The most promising research directions for elucidating NWMN_1849 function combine cutting-edge technologies with classical approaches:

• Structural biology approaches:

  • High-resolution structure determination via X-ray crystallography or cryo-EM

  • Molecular dynamics simulations to understand conformational changes

  • Ligand binding site identification and characterization

• Systems biology integration:

  • Network analysis to position NWMN_1849 within S. aureus cellular pathways

  • Multi-omics data integration to understand contextual function

  • Mathematical modeling of NWMN_1849's role in cellular processes

• Translational applications:

  • Assessment as a potential diagnostic biomarker for S. aureus infections

  • Evaluation as a vaccine candidate or therapeutic target

  • Development of structure-based inhibitors if enzymatic activity is identified

• Evolutionary perspectives:

  • Comparative analysis across bacterial species to understand conservation

  • Investigation of selective pressures shaping NWMN_1849 evolution

  • Horizontal gene transfer assessment in the context of pathogen evolution

• Novel methodology application:

  • Single-molecule techniques to study dynamic interactions

  • Live-cell imaging to track protein localization and dynamics

  • High-throughput mutagenesis approaches like deep mutational scanning

As with all scientific endeavors, these approaches should be pursued with careful experimental design that incorporates appropriate controls, statistical power considerations, and replication . The uncharacterized nature of NWMN_1849 presents both challenges and opportunities, making it an excellent candidate for innovative research approaches that could yield insights into fundamental aspects of S. aureus biology.

How can researchers contribute to the collective understanding of UPF0316 family proteins through studies of NWMN_1849?

Research on NWMN_1849 has the potential to advance understanding of the entire UPF0316 protein family through several strategic approaches:

• Establish NWMN_1849 as a model protein:

  • Develop a comprehensive toolkit for NWMN_1849 study (antibodies, expression constructs, purification protocols)

  • Create a standardized set of assays for functional characterization

  • Share resources openly with the research community to facilitate comparative studies

• Perform comparative studies across UPF0316 family members:

  • Extend findings from NWMN_1849 to homologs in other bacterial species

  • Identify conserved and divergent functional features

  • Test functional complementation between family members

• Establish a systematic classification framework:

  • Develop a functional classification system for UPF0316 proteins

  • Map sequence variations to functional differences

  • Create predictive models for function based on sequence features

• Contribute to community resources:

  • Deposit structures and functional data in public databases

  • Develop specialized databases or knowledge bases for UPF0316 proteins

  • Participate in community annotation projects

• Apply consistent methodological approaches:

  • Develop standardized protocols for UPF0316 protein characterization

  • Use consistent reporting formats to facilitate meta-analyses

  • Implement rigorous experimental design principles to ensure reproducibility

The systematic characterization of NWMN_1849 could serve as a template for studies of other uncharacterized protein families, potentially accelerating functional annotation across bacterial proteomes. This would contribute significantly to closing the gap between sequence data accumulation and functional characterization in the era of high-throughput genomics.