Lipoproteins in bacteria

摘要: Covalent modification of membrane proteins with lipids appears to be ubiquitous in all living cells. The major outer (Braun's) lipoprotein E. coli, the prototype bacterial lipoproteins, is first synthesized as a precursor protein. Analysis signal sequences 26 distinct precursors has revealed consensus sequence modification/processing site Leu-(Ala, Ser)-(Gly, Ala)-Cys at -3 +1 positions which would represent cleavage region about three-fourth bacteria. Unmodified prolipoprotein putative undergoes sequential and processing reactions catalyzed by glyceryl transferase, O-acyl transferase(s), peptidase (signal II), N-acyl transferase form mature lipoprotein. Like exported proteins, export requires functional SecA, SecY, SecD proteins. Thus are through common pathway accessible both I II. rapidly increasing list lipid-modified prokaryotic well eukaryotic cells indicates that lipoproteins comprise diverse group structurally functionally They share structural feature derived from biosynthetic pathway.