2jgp: Difference between revisions

The crystal structure of the bidomain PCP-C from modules 5 and 6 of the nonribosomal tyrocidine synthetase TycC was determined at 1.8 A resolution. The bidomain structure reveals a V-shaped condensation domain, the canyon-like active site groove of which is associated with the preceding peptidyl carrier protein (PCP) domain at its donor side. The relative arrangement of the PCP and the peptide bond-forming condensation (C) domain places the active sites approximately 50 A apart. Accordingly, this PCP-C structure represents a conformational state prior to peptide transfer from the donor-PCP to the acceptor-PCP domain, implying the existence of additional states of PCP-C domain interaction during catalysis. Additionally, PCP-C exerts a mode of cyclization activity that mimics peptide bond formation catalyzed by C domains. Based on mutational data and pK value analysis of active site residues, it is suggested that nonribosomal peptide bond formation depends on electrostatic interactions rather than on general acid/base catalysis.

[[Category: Essen, L O.]]

[[Category: Knappe, T A.]]

[[Category: Marahiel, M A.]]

[[Category: Samel, S A.]]

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