title: Crystal structure and biophysical characterisation of Helicobacter pylori phosphopantetheine adenylyltransferase.
abstract: Helicobacter pylori is a bacterium that causes chronic active gastritis and peptic ulcers. Drugs targeting H. pylori phosphopantetheine adenylyltransferase (HpPPAT), which is involved in CoA biosynthesis, may be useful. Herein, we report the expression in Escherichia coli and purification of recombinant HpPPAT and describe a crystal structure for an HpPPAT/CoA complex. As is the case for E. coli PPAT (EcPPAT), HpPPAT is hexameric in solution and as a crystal. Each protomer has a well-packed dinucleotide-binding fold in which CoA binds. Structural characterisation demonstrated that CoA derived from the E. coli expression system bound tightly to HpPPAT, presumably to initiate feedback inhibition. However, the interactions between the active-site residues of HpPPAT and CoA are not identical to those of other PPATs. Finally, CoA binding affects HpPPAT thermal denaturation.
authors.affiliation: Institute of Bioinformatics and Structural Biology, College of Life Sciences, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan.
authors.forename: Chao-Sheng
authors.initials: CS
authors.lastname: Cheng
authors.forename: Chih-Hao
authors.initials: CH
authors.lastname: Chen
authors.forename: Yong-Chun
authors.initials: YC
authors.lastname: Luo
authors.forename: Wen-Tin
authors.initials: WT
authors.lastname: Chen
authors.forename: Shun-Ya
authors.initials: SY
authors.lastname: Chang
authors.forename: Ping-Chiang
authors.initials: PC
authors.lastname: Lyu
authors.forename: Mou-Chieh
authors.initials: MC
authors.lastname: Kao
authors.forename: Hsien-Sheng
authors.initials: HS
authors.lastname: Yin
mesh_terms: D000595:Amino Acid Sequence; D003065:Coenzyme A / Q000737:chemistry; D018360:Crystallography, X-Ray; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D016480:Helicobacter pylori / Q000201:enzymology*; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000737:chemistry* / Q000235:genetics; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011994:Recombinant Proteins; D009713:Nucleotidyltransferases; C022315:pantetheine-phosphate adenylyltransferase; D003065:Coenzyme A