A new beta-hydroxyacyl-acyl carrier protein dehydratase (FabZ) from Helicobacter pylori: Molecular cloning, enzymatic characterization, and structural modeling.
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.
Liu
Weizhi
W
Shanghai Institute for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, China.
Luo
Cheng
C
Han
Cong
C
Peng
Shuying
S
Yang
Yiming
Y
Yue
Jianming
J
Shen
Xu
X
Jiang
Hualiang
H
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
D006836:Hydro-Lyases; C036180:beta-hydroxyacyl-(acyl-carrier-protein)dehydrase