Recombinant Sulfolobus islandicus UPF0290 protein YG5714_1358 (YG5714_1358)

What is the molecular composition of the Recombinant Sulfolobus islandicus UPF0290 protein YG5714_1358?

The recombinant protein consists of 166 amino acids (full length 1-166) with an N-terminal His-tag. The protein has the UniProt ID C3NE86 and is also known as carS, CDP-archaeol synthase, or CDP-2,3-bis-(O-geranylgeranyl-sn-glycerol synthase. The complete amino acid sequence is:

MSIAYDLLLSILIYLPAFVANGSGPFIKRGTPIDFGKNFVDGRRLFGDGKTFEGLIVALTFGTTVGVIISKFFTAEWTLISFLESLFAMIGDMIGAFIKRRLGIPRGGRVLGLDQLDFVLGASLILVLMRVNITWYQFLFICGLAFFLHQGTNYVAYLLKIKNVPW

The protein is typically expressed in E. coli systems and purified to greater than 90% homogeneity as determined by SDS-PAGE analysis.

What are the recommended storage and handling conditions for maintaining protein stability?

To maintain optimal stability, store the lyophilized protein powder at -20°C/-80°C upon receipt. For reconstitution, use deionized sterile water to achieve a concentration of 0.1-1.0 mg/mL and add glycerol to a final concentration of 5-50% (with 50% being standard) for long-term storage at -20°C/-80°C. Working aliquots can be stored at 4°C for up to one week, but repeated freeze-thaw cycles should be avoided. The storage buffer consists of Tris/PBS-based solution with 6% trehalose at pH 8.0 .

What is known about the native function of YG5714_1358 in Sulfolobus islandicus?

Based on gene annotation, YG5714_1358 (carS) likely functions as a CDP-archaeol synthase involved in archaeal membrane lipid biosynthesis. The protein belongs to the UPF0290 family, which is widely distributed across archaeal species. In the context of S. islandicus biology, this protein would be critical for the synthesis of the unique ether-linked isoprenoid lipids characteristic of archaeal membranes, which are essential for survival in the extreme thermoacidophilic conditions where these organisms thrive .

How should I design experiments to assess the enzymatic activity of YG5714_1358?

For enzymatic characterization of YG5714_1358, consider the following methodological approach:

• Temperature optimization: Design assays that function at 70-85°C to reflect the native thermophilic environment of S. islandicus.

• Buffer selection: Use acid-stable buffers (pH 3-5) that maintain integrity at high temperatures.

• Substrate preparation: For CDP-archaeol synthase activity, prepare archaeol and CTP substrates and monitor their conversion to CDP-archaeol.

• Detection methods: Employ thin-layer chromatography, HPLC, or mass spectrometry to detect reaction products.

• Controls: Include heat-inactivated enzyme samples and reactions without either substrate.

• Thermostability analysis: Assess activity after pre-incubation at various temperatures to determine thermal stability profile.

Remember that standard enzymatic assay conditions developed for mesophilic proteins may not be suitable without significant modifications .

What genetic manipulation strategies can be applied to study YG5714_1358 function in vivo?

Several genetic approaches have been developed specifically for S. islandicus:

• Marker exchange: Use established pyrEF marker systems for gene knockout or replacement strategies.

• CRISPR-Cas based genome editing: S. islandicus naturally contains CRISPR systems that have been adapted for genome editing.

• Transformation protocol: Electroporation of S. islandicus (as described by Deng et al.) with careful buffer optimization for thermophilic conditions.

• Conditional expression systems: Implement inducible promoters for controlled expression.

• Counterselection systems: The apt/6-methylpurine system has been adapted for S. islandicus.

These approaches allow for sophisticated genetic manipulation despite the challenges of working with hyperthermophilic archaea .

What considerations should be made when designing recombination experiments with S. islandicus strains carrying YG5714_1358 variants?

When designing recombination experiments, consider:

• Marker positioning: Place selectable markers at appropriate distances from the target gene, as recombination frequency decreases with distance from integration sites.

• Strain selection: Different S. islandicus strains show varying recombination efficiencies (e.g., the "Red" group shows higher exchange rates).

• Plasmid influence: The presence of integrated conjugative plasmids (like pM164) significantly influences recombination frequencies near their integration sites.

• Essential gene considerations: If YG5714_1358 is essential, employ conditional strategies rather than direct knockouts.

• Recombination mechanism: Account for both plasmid-mediated and host-encoded marker exchange mechanisms that operate differently.

• Verification strategy: Plan for genomic analysis to map recombinant tracts and confirm successful recombination events .

How can evolutionary genomics approaches be integrated into YG5714_1358 functional studies?

To leverage evolutionary genomics for YG5714_1358 functional investigation:

• Comparative genomics: Analyze YG5714_1358 conservation across the ten completely sequenced S. islandicus strains to identify conserved functional domains.

• Population genomics: Examine natural variation patterns in YG5714_1358 across S. islandicus isolates from different geographic locations.

• Recombination analysis: Study recombination patterns around YG5714_1358 to identify potential functional linkage with neighboring genes.

• Selection pressure analysis: Calculate dN/dS ratios to determine evolutionary constraints on different protein regions.

• Ancestral sequence reconstruction: Infer the evolutionary trajectory of YG5714_1358 and identify key adaptive mutations.

S. islandicus has been developed as a model system for combining evolutionary and molecular biology approaches in Archaea, making it ideal for such integrated studies .

What approaches can be used to investigate protein-protein interactions involving YG5714_1358 under extremophilic conditions?

For protein interaction studies under extremophilic conditions:

• Pull-down assays: Utilize the His-tag for affinity purification under high-temperature conditions.

• Crosslinking methods: Employ thermostable crosslinkers followed by mass spectrometry analysis.

• Thermal-adapted two-hybrid systems: Modify yeast or bacterial two-hybrid systems for high-temperature compatibility.

• Co-immunoprecipitation: Develop antibodies against YG5714_1358 for native protein complex isolation.

• Proximity labeling: Adapt BioID or APEX2 approaches for high-temperature applications.

• Computational prediction: Use archaeal-specific interaction prediction algorithms to identify potential binding partners.

All experimental approaches must be adapted to function at high temperatures (70-85°C) and acidic pH (3-5) to reflect native conditions .

How should researchers interpret transcriptomic data to understand YG5714_1358 regulation in S. islandicus?

When analyzing transcriptomic data:

• Expression correlation analysis: Identify genes with expression patterns that correlate with YG5714_1358 across different conditions.

• Operon structure determination: Analyze RNA-seq data to confirm if YG5714_1358 is part of a polycistronic transcript.

• Transcription start site mapping: Use 5' RACE or similar techniques to precisely map the transcriptional start site.

• Regulatory element identification: Analyze upstream regions for archaeal promoter elements and potential transcription factor binding sites.

• Comparative expression analysis: Compare expression patterns across different S. islandicus strains to identify strain-specific regulation.

This approach can position YG5714_1358 within the broader genomic and metabolic context of S. islandicus .

What statistical approaches are recommended for analyzing enzyme kinetics data from YG5714_1358 assays?

For robust enzyme kinetics analysis:

• Non-linear regression: Fit data to appropriate enzyme kinetics models (Michaelis-Menten, allosteric, etc.) using software like GraphPad Prism or R.

• Temperature dependence modeling: Use Arrhenius plots to determine activation energy and temperature optimum.

• Thermodynamic parameter calculation: Determine ΔH, ΔS, and ΔG values to characterize the reaction energetics.

• Global fitting approaches: When testing multiple conditions or inhibitors, employ global fitting to improve parameter estimation.

• Bayesian analysis: Consider Bayesian approaches for more robust parameter estimation with appropriate prior distributions.

• Bootstrapping: Use bootstrapping to estimate confidence intervals for kinetic parameters.

These statistical approaches help account for the unique challenges of analyzing enzyme data obtained under extreme conditions .

What structural biology techniques are most appropriate for studying the three-dimensional structure of YG5714_1358?

For structural characterization of thermostable proteins like YG5714_1358:

These approaches can provide insights into how this extremophilic protein maintains functionality at high temperatures .

How can researchers distinguish between direct and indirect effects when analyzing YG5714_1358 knockout phenotypes?

To establish causality in knockout studies:

• Complementation analysis: Reintroduce wild-type and mutant versions of YG5714_1358 to confirm phenotype rescue.

• Conditional expression systems: Use inducible promoters to create tunable expression levels.

• Point mutation strategy: Create specific activity-abolishing mutations rather than whole gene deletions.

• Temporal analysis: Monitor phenotypic changes immediately following gene inactivation versus long-term adaptation.

• Multi-omics integration: Combine transcriptomic, proteomic, and metabolomic analyses to trace causality through metabolic networks.

• Synthetic lethality screening: Identify genetic interactions that may explain complex phenotypes.

This multi-faceted approach helps establish direct functional relationships and distinguish them from compensatory or pleiotropic effects .

How can YG5714_1358 research be integrated with broader studies of archaeal-specific metabolic pathways?

To position YG5714_1358 within archaeal metabolism:

• Metabolic reconstruction: Map YG5714_1358 within the context of S. islandicus lipid biosynthesis pathways.

• Comparative genomics: Analyze gene neighborhoods across different archaeal species to identify conserved metabolic modules.

• Metabolic flux analysis: Develop methods to trace isotopically labeled precursors through archaeal lipid biosynthesis.

• Evolutionary analysis: Compare enzyme properties across the archaeal domain to identify specialized adaptations.

• Systems biology modeling: Integrate YG5714_1358 into genome-scale metabolic models of archaeal metabolism.

This integration helps understand not just the individual protein but its role in the unique archaeal metabolic landscape .

What differences in experimental design should be considered when comparing YG5714_1358 with homologous proteins from mesophilic organisms?

When conducting comparative studies:

• Temperature adaptation: Run parallel assays at both optimal temperatures for each protein (high temperature for YG5714_1358, moderate for mesophilic homologs).

• Buffer compatibility: Design buffer systems that maintain similar ionic strength and pH effects across different temperature ranges.

• Substrate availability: Account for different substrate stabilities at high versus moderate temperatures.

• Reaction kinetics: Adjust sampling timeframes to account for potentially faster reaction rates at higher temperatures.

• Protein stability controls: Include appropriate controls for protein stability throughout the experimental timeframe.

• Sequence-structure-function relationships: Create chimeric proteins or targeted mutations to isolate thermostability determinants.

These considerations ensure fair comparisons between proteins evolved for different thermal environments .

What are the most common challenges in expressing and purifying active YG5714_1358, and how can they be addressed?

Common challenges and solutions include:

Each challenge requires systematic optimization with controls at each step to ensure protein quality .

How can researchers troubleshoot inconsistent results in YG5714_1358 activity assays?

To address reproducibility issues:

• Temperature control: Verify precise temperature maintenance throughout the assay, as small fluctuations can significantly affect thermophilic enzyme activity.

• Buffer stability: Confirm buffer stability at high temperatures; some components may degrade or precipitate.

• Substrate quality: Validate substrate purity and stability under assay conditions.

• Enzyme batch consistency: Implement quality control measures for each protein preparation (activity tests, thermal shift assays).

• Oxygen sensitivity: If relevant, ensure consistent anaerobic conditions throughout the experiment.

• Equipment calibration: Regularly calibrate high-temperature equipment as performance may drift.

• Statistical validation: Apply appropriate statistical tests to determine if variations are within expected experimental error.

Systematic troubleshooting using this approach can identify sources of variability and improve experimental reproducibility .

How can CRISPR-Cas technology be optimized for studying YG5714_1358 function in S. islandicus?

For optimizing CRISPR-Cas approaches:

• Guide RNA design: Select targets with minimal off-target effects, accounting for the high GC content often found in thermophilic organisms.

• Delivery method: Optimize electroporation protocols specifically for S. islandicus strains.

• Temperature adaptation: Ensure the CRISPR-Cas system components function at the high growth temperature of S. islandicus.

• Selection strategy: Integrate appropriate selection markers for the extreme growth conditions.

• Verification methods: Develop PCR and sequencing protocols that account for the high GC content and potential secondary structures.

• Inducible systems: Consider implementing thermoinducible CRISPR systems for temporal control.

S. islandicus naturally contains CRISPR systems that have been harnessed for genetic manipulation, making it particularly amenable to these approaches .

What considerations should be made when designing multi-omics experiments to understand YG5714_1358 function in the context of cellular physiology?

For effective multi-omics experimental design:

• Sample preparation: Develop protocols that rapidly quench metabolism to prevent changes during sample processing.

• Transcriptomics: Consider strand-specific RNA-seq to resolve overlapping transcripts common in archaeal genomes.

• Proteomics: Adapt protein extraction and digestion protocols for the highly stable proteins of thermophiles.

• Metabolomics: Include methods specific for archaeal lipid detection and quantification.

• Data integration: Employ computational approaches that can integrate multi-omics data from extremophiles.

• Temporal resolution: Design time-course experiments to capture rapid metabolic shifts.

• Statistical power: Ensure sufficient biological replicates to account for the potentially high variability in extremophile cultures.

This comprehensive approach allows for understanding YG5714_1358 function within the broader context of S. islandicus cellular physiology .

What emerging technologies might advance our understanding of YG5714_1358 structure-function relationships?

Promising emerging technologies include:

• Cryo-electron tomography: For visualizing proteins in their native cellular context at high resolution.

• Single-molecule enzymology: Adapted for high-temperature conditions to observe individual enzyme molecules.

• Nanopore protein sequencing: For direct analysis of protein modifications and variants.

• In-cell NMR spectroscopy: For studying protein dynamics under native-like conditions.

• Advanced computational approaches: Including AlphaFold2 and similar tools optimized for archaeal proteins.

• High-throughput mutagenesis combined with deep sequencing: For comprehensive structure-function mapping.

• Microfluidic platforms: For parallelized enzyme assays under precisely controlled conditions.

These technologies promise to provide unprecedented insights into how extremophilic proteins like YG5714_1358 function under extreme conditions .

How might research on YG5714_1358 contribute to our broader understanding of archaeal evolution and adaptation to extreme environments?

Research on YG5714_1358 can advance our understanding of:

• Molecular adaptations to thermophily: Identifying specific structural features that confer thermostability.

• Archaeal-specific metabolic pathways: Understanding unique aspects of archaeal membrane biosynthesis.

• Evolutionary history of Archaea: Tracing the evolution of key metabolic processes through comparative studies.

• Horizontal gene transfer: Investigating how genes like YG5714_1358 might have been shared across archaeal lineages.

• Adaptation mechanisms: Revealing how enzymes evolve to function under multiple extreme conditions simultaneously.

• Origin of cellular life: Providing insights into how early life may have evolved in extreme environments similar to those inhabited by S. islandicus.

This research has implications beyond the specific protein, contributing to fundamental questions in evolutionary biology and astrobiology .

What innovative approaches can be developed for studying YG5714_1358 interactions with archaeal membrane components?

Innovative methodological approaches include:

• Archaeal lipid nanodiscs: Develop nanodisc systems using archaeal lipids to study membrane protein interactions.

• High-temperature atomic force microscopy: Adapt AFM for visualizing protein-membrane interactions at elevated temperatures.

• Thermostable fluorophores: Develop fluorescent probes stable at high temperatures for FRET and other fluorescence-based interaction studies.

• Archaeal membrane mimetics: Create synthetic systems that replicate the unique composition of archaeal membranes.

• In silico molecular dynamics: Implement specialized force fields for simulating archaeal membrane systems.

• Label-free interaction analysis: Adapt surface plasmon resonance and related techniques for high-temperature applications.

These approaches could overcome the significant technical challenges in studying extremophilic membrane-associated proteins .

How can synthetic biology approaches be adapted for functional studies of YG5714_1358 in heterologous systems?

For synthetic biology applications:

• Codon optimization: Design gene variants optimized for expression in model organisms while maintaining key structural features.

• Chassis selection: Identify appropriate host organisms that can tolerate the expression of thermophilic proteins.

• Chimeric protein design: Create fusion proteins combining thermostable domains with mesophilic functional domains.

• Minimal archaeal cell systems: Develop simplified archaeal-based expression systems.

• Directed evolution: Implement high-throughput screening methods to evolve YG5714_1358 for function in mesophilic conditions.

• Orthogonal translation systems: Incorporate non-canonical amino acids to probe function or create novel properties.

These approaches could bridge the gap between studying extremophilic proteins and applying their unique properties in biotechnological applications .