3S3L image
Entry Detail
PDB ID:
3S3L
Keywords:
Title:
Crystal Structure of CerJ from Streptomyces tendae
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2011-05-18
Release Date:
2011-12-21
Method Details:
Experimental Method:
Resolution:
2.00 Å
R-Value Free:
0.20
R-Value Work:
0.16
R-Value Observed:
0.16
Space Group:
P 41 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:CerJ
Chain IDs:A, B
Chain Length:357
Number of Molecules:2
Biological Source:Streptomyces tendae
Primary Citation
A ketosynthase homolog uses malonyl units to form esters in cervimycin biosynthesis.
Nat.Chem.Biol. 8 154 161 (2011)
PMID: 22179067 DOI: 10.1038/nchembio.746

Abstact

Ketosynthases produce the carbon backbones of a vast number of biologically active polyketides by catalyzing Claisen condensations of activated acyl and malonyl building blocks. Here we report that a ketosynthase homolog from Streptomyces tendae, CerJ, unexpectedly forms malonyl esters during the biosynthesis of cervimycin, a glycoside antibiotic against methicillin-resistant Staphylococcus aureus (MRSA). Deletion of cerJ yielded a substantially more active cervimycin variant lacking the malonyl side chain, and in vitro biotransformations revealed that CerJ is capable of transferring malonyl, methylmalonyl and dimethylmalonyl units onto the glycoside. According to phylogenetic analyses and elucidation of the crystal structure, CerJ is functionally and structurally positioned between the ketosynthase catalyzing Claisen condensations and acyl-ACP shuttles, and it features a noncanonical catalytic triad. Site-directed mutagenesis and structures of CerJ in complex with substrates not only allowed us to establish a model for the reaction mechanism but also provided insights into the evolution of this important subclass of the thiolase superfamily.

Legend

Protein

Chemical

Disease

Primary Citation of related structures