4ZJB: Crystal structure of (3R)-Hydroxyacyl-Acyl Carrier Protein Dehydratase(FabZ) in complex with holo-ACP from Helicobacter pylori

Fatty acid biosynthesis (FAS) is a vital process in cells. Fatty acids are essential for cell assembly and cellular metabolism. Abnormal FAS directly correlates with cell growth delay and human diseases, such as metabolic syndromes and various cancers. The FAS system utilizes an acyl carrier protein (ACP) as a transporter to stabilize and shuttle the growing fatty acid chain throughout enzymatic modules for stepwise catalysis. Studying the interactions between enzymatic modules and ACP is, therefore, critical for understanding the biological function of the FAS system. However, the information remains unclear due to the high flexibility of ACP and its weak interaction with enzymatic modules. We present here a 2.55 A crystal structure of type II FAS dehydratase FabZ in complex with holo-ACP, which exhibits a highly symmetrical FabZ hexamer-ACP3 stoichiometry with each ACP binding to a FabZ dimer subunit. Further structural analysis, together with biophysical and computational results, reveals a novel dynamic seesaw-like ACP binding and catalysis mechanism for the dehydratase module in the FAS system, which is regulated by a critical gatekeeper residue (Tyr100 in FabZ) that manipulates the movements of the beta-sheet layer. These findings improve the general understanding of the dehydration process in the FAS system and will potentially facilitate drug and therapeutic design for diseases associated with abnormalities in FAS.
PDB ID: 4ZJBDownload
MMDB ID: 144470
PDB Deposition Date: 2015/4/29
Updated in MMDB: 2016/11
Experimental Method:
x-ray diffraction
Resolution: 2.55  Å
Source Organism:
Similar Structures:
Biological Unit for 4ZJB: trimeric; determined by author and by software (PISA)
Molecular Components in 4ZJB
Label Count Molecule
Proteins (3 molecules)
3-hydroxyacyl-[acyl-carrier-protein] Dehydratase Fabz
Molecule annotation
Acyl Carrier Protein
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB