1U6Z

Structure of an E. coli Exopolyphosphatase: Insight into the processive hydrolysis of polyphosphate and its regulation

1U6Z の概要

• エントリーDOI: 10.2210/pdb1u6z/pdb
• 分子名称: Exopolyphosphatase, SULFATE ION (3 entities in total)
• 機能のキーワード: alpha/beta protein, askha (acetate and sugar kinases, hsc70, actin) superfamily, hd metal dependent phosphohydrolase superfamily, polyphosphate, twenty-nine sulfates, hydrolase
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cell membrane; Peripheral membrane protein: P29014
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 119209.53

構造登録者

Hasson, M.S.,Alvarado, J.,Sanders, D.A. (登録日: 2004-08-02, 公開日: 2005-12-06, 最終更新日: 2024-02-14)

主引用文献

Alvarado, J.,Ghosh, A.,Janovitz, T.,Jauregui, A.,Hasson, M.S.,Sanders, D.A.
Origin of exopolyphosphatase processivity: Fusion of an ASKHA phosphotransferase and a cyclic nucleotide phosphodiesterase homolog.
Structure, 14:1263-1272, 2006

PubMed Abstract: The Escherichia coli Ppx protein is an exopolyphosphatase that degrades long-chain polyphosphates in a highly processive reaction. It also hydrolyzes the terminal 5' phosphate of the modified nucleotide guanosine 5' triphosphate 3' diphosphate (pppGpp). The structure of Ppx has been determined to 1.9 A resolution by X-ray crystallography. The exopolyphosphatase is an ASKHA (acetate and sugar kinases, Hsp70, actin) phosphotransferase with an active site found in a cleft between the two amino-terminal domains. Analysis of the active site indicates that among the ASKHA phosphotranferases of known structure, Ppx is the closest to the ectonucleoside triphosphate diphosphohydrolases. A third domain forms a six-helix claw that is similar to the catalytic core of the eukaryotic cyclic nucleotide phosphodiesterases. Most of the 29 sulfate ions bound to the Ppx dimer occupy sites where the polyP chain likely binds. An aqueduct that passes through the enzyme provides a physical basis for the enzyme's high processivity.

PubMed: 16905100
DOI: 10.1016/j.str.2006.06.009

実験手法

X-RAY DIFFRACTION (1.9 Å)