title: Structure of inorganic pyrophosphatase from Helicobacter pylori.
abstract: Inorganic pyrophosphatase (PPase) is a ubiquitous cytosolic enzyme which catalyzes the hydrolysis of inorganic pyrophosphate (PPi) to orthophosphate (Pi). The crystal structure of inorganic pyrophosphatase from Helicobacter pylori (H-PPase) has been solved by MAD and refined to an R factor of 20.6% at 2.6 A resolution. The crystallographic asymmetric unit contains a homohexameric H-PPase arranged as a dimer of trimers. While most of the structural elements of PPases are highly conserved in H-PPase, some unique structural features are localized in the flexible loops near the active site, suggesting that the structural flexibility of these loops is required for the catalytic efficiency of PPase.
authors.affiliation: Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea.
authors.forename: Chun Ai
authors.initials: CA
authors.lastname: Wu
authors.forename: Neratur K
authors.initials: NK
authors.lastname: Lokanath
authors.forename: Dong Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Park
authors.forename: Hye Yeon
authors.initials: HY
authors.lastname: Hwang
authors.forename: Seong Tae
authors.initials: ST
authors.lastname: Kim
authors.forename: Se Won
authors.initials: SW
authors.lastname: Suh
authors.forename: Kyeong Kyu
authors.initials: KK
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005784:Gene Amplification; D016480:Helicobacter pylori / Q000201:enzymology* / Q000235:genetics; D043564:Inorganic Pyrophosphatase / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D011487:Protein Conformation; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D043564:Inorganic Pyrophosphatase