PDBsum entry 1wpm

Hydrolase

PDB id: 1wpm

Contents

Protein chains

307 a.a. *

Ligands

SO4 ×4

PG4 ×3

Waters ×538

* Residue conservation analysis

PDB id:

1wpm

Name:

Hydrolase

Title:

Structure of bacillus subtilis inorganic pyrophosphatase

Structure:

Manganese-dependent inorganic pyrophosphatase. Chain: a, b. Synonym: pyrophosphate phospho-hydrolase, ppase. Engineered: yes

Source:

Bacillus subtilis. Organism_taxid: 1423. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Biol. unit:

Dimer (from PQS)

Resolution:

2.05Å R-factor: 0.192 R-free: 0.248

Authors:

I.P.Fabrichniy,L.Lehtio,A.Salminen,A.A.Baykov,R.Lahti,A.Goldman

Key ref:

I.P.Fabrichniy et al. (2004). Structural studies of metal ions in family II pyrophosphatases: the requirement for a Janus ion. Biochemistry, 43, 14403-14411. PubMed id: 15533045 DOI: 10.1021/bi0484973

Date:

09-Sep-04 Release date: 23-Nov-04

Protein chains

P37487  (PPAC_BACSU) -  Manganese-dependent inorganic pyrophosphatase from Bacillus subtilis (strain 168)

Seq: 309 a.a.

Struc: 307 a.a.

Enzyme reactions

• Enzyme class: E.C.3.6.1.1 - inorganic diphosphatase.
• Reaction: diphosphate + H2O = 2 phosphate + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1021/bi0484973

Biochemistry 43:14403-14411 (2004)

PubMed id: 15533045

Structural studies of metal ions in family II pyrophosphatases: the requirement for a Janus ion.

I.P.Fabrichniy, L.Lehtiö, A.Salminen, A.B.Zyryanov, A.A.Baykov, R.Lahti, A.Goldman.

ABSTRACT

Family II inorganic pyrophosphatases (PPases) constitute a new evolutionary group of PPases, with a different fold and mechanism than the common family I enzyme; they are related to the "DHH" family of phosphoesterases. Biochemical studies have shown that Mn(2+) and Co(2+) preferentially activate family II PPases; Mg(2+) partially activates; and Zn(2+) can either activate or inhibit (Zyryanov et al., Biochemistry, 43, 14395-14402, accompanying paper in this issue). The three solved family II PPase structures did not explain the differences between the PPase families nor the metal ion differences described above. We therefore solved three new family II PPase structures: Bacillus subtilis PPase (Bs-PPase) dimer core bound to Mn(2+) at 1.3 A resolution, and, at 2.05 A resolution, metal-free Bs-PPase and Streptococcus gordonii (Sg-PPase) containing sulfate and Zn(2+). Comparison of the new and old structures of various family II PPases demonstrates why the family II enzyme prefers Mn(2+) or Co(2+), as an activator rather than Mg(2+). Both M1 and M2 undergo significant changes upon substrate binding, changing from five-coordinate to octahedral geometry. Mn(2+) and Co(2+), which readily adopt different coordination states and geometries, are thus favored. Combining our structures with biochemical data, we identified M2 as the high-affinity metal site. Zn(2+) activates in the M1 site, where octahedral geometry is not essential for catalysis, but inhibits in the M2 site, because it is unable to assume octahedral geometry but remains trigonal bipyramidal. Finally, we propose that Lys205-Gln81-Gln80 form a hydrophilic channel to speed product release from the active site.