- Source: Protein K (porin)
Structure
Proteinase K has a catalytic triad of Ser 224, His 69, and Asp 39. Two peptide chains recognize substrates, 99-104 and 132–136. There is also a cysteine free near His 69.
Protein K is a porin expressed in some pathogenic strains of E. coli bacteria. It has a molecular weight of about 40 kDa and is localized to the outer membrane, through which it allows both inorganic and organic ions to pass. The addition of Protein K in the outer membrane proven to cause an increased rate of uptake of nutrients and a faster growth rate relative to the parental porin- strain.
The strains in which protein K has been identified are encapsulated, or surrounded by a poly-sialic acid capsule that renders them more resistant to phagocytosis by cells in the immune system.
References
Whitfield C, Hancock RE, Costerson JW. (1983). Outer membrane protein K of Escherichia coli: purification and pore-forming properties in lipid bilayer membranes. J Bacteriol 156(2): 873-879
Sutcliffe J, Blumenthal R, Walter A, Foulds J. (1983). Escherichia coli outer membrane protein K is a porin. J Bacteriol 156(2): 867-872
Bliss JM, Solver RP. (1996). Coating the surface: a model for expression of capsular polysialic acid in Escherichia coli K1. Mol Microbiol 21:221.
Kata Kunci Pencarian:
- Mitokondria
- Helicobacter pylori
- Widal
- Karbapenem
- Protein K (porin)
- Porin (protein)
- Protein K
- Transmembrane protein
- General bacterial porin family
- Membrane transport protein
- Protein design
- Nucleoside-specific porin
- Lambda phage
- EnvZ/OmpR two-component system
