4BKQ: Enoyl-acp Reductase From Yersinia Pestis (wildtype)with Cofactor Nadh

The enoyl-ACP reductase (ENR) catalyzes the last reaction in the elongation cycle of the bacterial type II fatty acid biosynthesis (FAS-II) pathway. While the FabI ENR is a well-validated drug target in organisms such as Mycobacterium tuberculosis and Staphylococcus aureus, alternate ENR isoforms have been discovered in other pathogens, including the FabV enzyme that is the sole ENR in Yersinia pestis (ypFabV). Previously, we showed that the prototypical ENR inhibitor triclosan was a poor inhibitor of ypFabV and that inhibitors based on the 2-pyridone scaffold were more potent [Hirschbeck, M. (2012) Structure 20 (1), 89-100]. These studies were performed with the T276S FabV variant. In the work presented here, we describe a detailed examination of the mechanism and inhibition of wild-type ypFabV and the T276S variant. The T276S mutation significantly reduces the affinity of diphenyl ether inhibitors for ypFabV (20-fold --> 100-fold). In addition, while T276S ypFabV generally displays an affinity for 2-pyridone inhibitors higher than that of the wild-type enzyme, the 4-pyridone scaffold yields compounds with similar affinity for both wild-type and T276S ypFabV. T276 is located at the N-terminus of the helical substrate-binding loop, and structural studies coupled with site-directed mutagenesis reveal that alterations in this residue modulate the size of the active site portal. Subsequently, we were able to probe the mechanism of time-dependent inhibition in this enzyme family by extending the inhibition studies to include P142W ypFabV, a mutation that results in a gain of slow-onset inhibition for the 4-pyridone PT156.
PDB ID: 4BKQDownload
MMDB ID: 119311
PDB Deposition Date: 2013/4/29
Updated in MMDB: 2016/06
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 4BKQ: dimeric; determined by author and by software (PISA)
Molecular Components in 4BKQ
Label Count Molecule
Proteins (2 molecules)
Putative Reductase Ypz3_3519(Gene symbol: YPO4104)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB