1l5a: Difference between revisions

[[Image:1l5a.gif|left|200px]]<br /><applet load="1l5a" size="350" color="white" frame="true" align="right" spinBox="true"  

Nonribosomal peptide synthetases (NRPSs) are large, multidomain enzymes that biosynthesize medically important natural products. We report the crystal structure of the free-standing NRPS condensation (C) domain VibH, which catalyzes amide bond formation in the synthesis of vibriobactin, a Vibrio cholerae siderophore. Despite low sequence identity, NRPS condensation enzymes are structurally related to chloramphenicol acetyltransferase (CAT) and dihydrolipoamide acyltransferases. However, although the latter enzymes are homotrimers, VibH is a monomeric pseudodimer. The VibH structure is representative of both NRPS condensation and epimerization domains, as well as the condensation-variant cyclization domains, which are all expected to be monomers. Surprisingly, despite favorable positioning in the active site, a universally conserved histidine important in CAT and in other C domains is not critical for general base catalysis in VibH.

1L5A is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1L5A OCA].  

[[Category: Keating, A E.]]

[[Category: Keating, T A.]]

[[Category: Marshall, C G.]]

[[Category: Walsh, C T.]]

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