Protein Family Models

The histidine phosphatase superfamily is so named because catalysis centres on a conserved His residue that is transiently phosphorylated during the catalytic cycle. Other conserved residues contribute to a 'phosphate pocket' and interact with the phospho group of substrate before, during and after its transfer to the His residue. Structure and sequence analyses show that different families contribute different additional residues to the 'phosphate pocket' and, more surprisingly, differ in the position, in sequence and in three dimensions, of a catalytically essential acidic residue. The superfamily may be divided into two main branches.The smaller branch 2 contains predominantly eukaryotic proteins. The catalytic functions in members include phytase, glucose-1-phosphatase and multiple inositol polyphosphate phosphatase. The in vivo roles of the mammalian acid phosphatases in branch 2 are not fully understood, although activity against lysophosphatidic acid and tyrosine-phosphorylated proteins has been demonstrated. [1]. 10329192. Crystal structure of Aspergillus niger pH 2.5 acid phosphatase at 2.4 A resolution. Kostrewa D, Wyss M, D'Arcy A, van Loon AP;. J Mol Biol 1999;288:965-974. [2]. 18092946. The histidine phosphatase superfamily: structure and function. Rigden DJ;. Biochem J. 2008;409:333-348. (from Pfam)

Date:

2024-10-16