Recombinant Escherichia coli Tyrosine-protein kinase wzc (wzc)

Definition of Recombinant Escherichia coli Tyrosine-Protein Kinase Wzc (Wzc)

Recombinant Escherichia coli Tyrosine-protein kinase Wzc (Wzc) is a protein-tyrosine kinase found in Escherichia coli . Wzc participates in the export of the extracellular polysaccharide colanic acid from the cell to the medium . It can be produced in various hosts, including yeast, E. coli, baculovirus, and mammalian cells, through recombinant technology .

Characteristics and Function

• Tyrosine Kinase Activity Wzc exhibits autophosphorylating protein-tyrosine kinase activity . It modifies itself exclusively at tyrosine residues . Phosphorylation of Tyr(569) leads to increased protein kinase activity, enabling Wzc to phosphorylate the five terminal tyrosines .

• Role in Polysaccharide Production Wzc is involved in the production of capsular (CPS) and released (RPS) polysaccharides . It functions as an inner membrane protein with an ATP-binding domain and predicted transmembrane segments .

• Interaction with Wzb Wzc interacts with Wzb, a phosphotyrosine-protein phosphatase also found in E. coli . Wzb can dephosphorylate Wzc, suggesting a regulatory mechanism connected with reversible protein phosphorylation on tyrosine .

Production and Availability

Recombinant Wzc can be produced in different expression systems :

• E. coli: Recombinant Wzc can be expressed in E. coli .

• Yeast: Yeast is also used as a host for the production of recombinant Wzc .

• Baculovirus: This system is used for producing recombinant Wzc .

• Mammalian Cells: Recombinant Wzc can be expressed in mammalian cells .

Research Findings

• Identification of Wzc and Wzb The study by Grangeasse, et al. demonstrated that E. coli cells contain both a protein-tyrosine kinase (Wzc) and a phosphotyrosine-protein phosphatase (Wzb) . Wzb can utilize Wzc as an endogenous substrate, suggesting a regulatory mechanism involving reversible protein phosphorylation on tyrosine .

• Structural Analysis Research has provided structural insights into the recognition of bacterial tyrosine kinases by counteracting phosphatases . Specific residues in Wzc and Wzb are crucial for their interaction .

• Role in EPS Production Studies have shown that Wzc and Wzb influence the amount and composition of extracellular polymeric substances (EPS) in cyanobacteria . Wzb can dephosphorylate Wzc in vitro, indicating a role in cyanobacterial EPS production .

Potential Applications

Recombinant enzymes like Wzc have various applications, particularly in diagnostics and drug discovery :

• Diagnostic Applications Recombinant enzymes enhance the sensitivity, specificity, and robustness of diagnostic assays, enabling the detection of low-abundance targets in complex biological samples .

• Drug Discovery Recombinant enzymes are useful in in vitro assays for reaction phenotyping and enzyme inhibition studies . They can help study interactions between drug candidates and individual enzymes .

Table: Wzc and Wzb Characteristics