2J82

Structural analysis of the PP2C Family Phosphatase tPphA from Thermosynechococcus elongatus

Summary for 2J82

• Entry DOI: 10.2210/pdb2j82/pdb
• Descriptor: PROTEIN SERINE-THREONINE PHOSPHATASE, CALCIUM ION, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: pp2c family phosphatase, hydrolase
• Biological source: SYNECHOCOCCUS ELONGATUS
• Total number of polymer chains: 1
• Total formula weight: 26865.74

Authors

Schlicker, C.,Kloft, N.,Forchhammer, K.,Becker, S. (deposition date: 2006-10-18, release date: 2007-11-06, Last modification date: 2024-05-08)

Primary citation

Schlicker, C.,Fokina, O.,Kloft, N.,Grune, T.,Becker, S.,Sheldrick, G.M.,Forchhammer, K.
Structural Analysis of the Pp2C Phosphatase Tppha from Thermosynechococcus Elongatus: A Flexible Flap Subdomain Controls Access to the Catalytic Site.
J.Mol.Biol., 376:570-, 2008

PubMed Abstract: The homologue of the phosphoprotein PII phosphatase PphA from Thermosynechococcus elongatus, termed tPphA, was identified and its structure was resolved in two different space groups, C222(1) and P4(1)2(1)2, at a resolution of 1.28 and 3.05 A, respectively. tPphA belongs to a large and widely distributed subfamily of Mg(2+)/Mn(2+)-dependent phosphatases of the PPM superfamily characterized by the lack of catalytic and regulatory domains. The core structure of tPphA shows a high degree of similarity to the two PPM structures identified so far. In contrast to human PP2C, but similar to Mycobacterium tuberculosis phosphatase PstP, the catalytic centre exhibits a third metal ion in addition to the dinuclear metal centre universally conserved in all PPM members. The fact that the third metal is only liganded by amino acids, which are universally conserved in all PPM members, implies that the third metal could be general for all members of this family. As a specific feature of tPphA, a flexible subdomain, previously recognized as a flap domain, could be revealed. Comparison of different structural isomers of tPphA as well as site-specific mutagenesis implied that the flap domain is involved in substrate binding and catalytic activity. The structural arrangement of the flap domain was accompanied by a large side-chain movement of an Arg residue (Arg169) at the basis of the flap. Mutation of this residue strongly impaired protein stability as well as catalytic activity, emphasizing the importance of this amino acid for the regional polysterism of the flap subdomain and confirming the assumption that flap domain flexibility is involved in catalysis.

PubMed: 18164312
DOI: 10.1016/J.JMB.2007.11.097

Experimental method

X-RAY DIFFRACTION (1.28 Å)