title: A new beta-hydroxyacyl-acyl carrier protein dehydratase (FabZ) from Helicobacter pylori: Molecular cloning, enzymatic characterization, and structural modeling.
abstract: Helicobacter pylori is a gram-negative pathogenic bacterium that causes peptic ulcer disease and gastric cancer, and studies of the related potent enzymes associated with this bacterium are urgent for the discovery of novel drug targets. In bacteria, beta-hydroxyacyl-acyl carrier protein (ACP) dehydratase (FabZ) is a potent enzyme in fatty acid biosynthesis and catalyzes the dehydration of beta-hydroxyacyl-ACP to trans-2-acyl-ACP. In this study, the cloning and enzymatic characterization of FabZ from H. pylori strain SS1 (HpFabZ) were reported, and the gene sequence of HpfabZ was deposited in the GenBank database. Enzyme dynamic analysis showed that HpFabZ had a K(m) of 82.6+/-4.3 microM toward its substrate analog crotonoyl-CoA. Dynamic light scattering and native-PAGE investigations suggested that HpFabZ exists as hexamer in native state. Enzymatic characterization and thermal-induced unfolding analysis based on circular dichroism spectral measurements indicated that HpFabZ is very stable against high temperature (90 degrees C). Such a high stability of HpFabZ was well elucidated by the strong H-bonds and hydrophobic interactions among the HpFabZ hexamer as investigated in the modeled HpFabZ hexamer structure. Our current study is hoped to provide useful information in better understanding the FabZ of H. pylori strain and further supply possible hints in the discovery of anti-bacterial compounds using HpFabZ as target.
authors.affiliation: Shanghai Institute for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China.
authors.forename: Weizhi
authors.initials: W
authors.lastname: Liu
authors.forename: Cheng
authors.initials: C
authors.lastname: Luo
authors.forename: Cong
authors.initials: C
authors.lastname: Han
authors.forename: Shuying
authors.initials: S
authors.lastname: Peng
authors.forename: Yiming
authors.initials: Y
authors.lastname: Yang
authors.forename: Jianming
authors.initials: J
authors.lastname: Yue
authors.forename: Xu
authors.initials: X
authors.lastname: Shen
authors.forename: Hualiang
authors.initials: H
authors.lastname: Jiang
mesh_terms: D000595:Amino Acid Sequence; D003198:Computer Simulation; D004789:Enzyme Activation; D004795:Enzyme Stability; D016480:Helicobacter pylori / Q000201:enzymology*; D006836:Hydro-Lyases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D006836:Hydro-Lyases; C036180:beta-hydroxyacyl-(acyl-carrier-protein)dehydrase