1znn
From Proteopedia
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Structure of the synthase subunit of PLP synthase
Overview
Pyridoxal 5'-phosphate (PLP, vitamin B6), a cofactor in many enzymatic, reactions, has two distinct biosynthetic routes, which do not coexist in, any organism. Two proteins, known as PdxS and PdxT, together form a PLP, synthase in plants, fungi, archaea, and some eubacteria. PLP synthase is a, heteromeric glutamine amidotransferase in which PdxT produces ammonia from, glutamine and PdxS combines ammonia with five- and three-carbon, phosphosugars to form PLP. In the 2.2-A crystal structure, PdxS is a, cylindrical dodecamer of subunits having the classic (beta/alpha)8 barrel, fold. PdxS subunits form two hexameric rings with the active sites, positioned on the inside. The hexamer and dodecamer forms coexist in, solution. A novel phosphate-binding site is suggested by bound sulfate., The sulfate and another bound molecule, methyl pentanediol, were used to, model the substrate ribulose 5-phosphate, and to propose catalytic roles, for residues in the active site. The distribution of conserved surfaces in, the PdxS dodecamer was used to predict a docking site for the glutaminase, partner, PdxT.
About this Structure
1ZNN is a Protein complex structure of sequences from Geobacillus stearothermophilus with SO4 and MRD as ligands. Full crystallographic information is available from OCA.
Reference
A new arrangement of (beta/alpha)8 barrels in the synthase subunit of PLP synthase., Zhu J, Burgner JW, Harms E, Belitsky BR, Smith JL, J Biol Chem. 2005 Jul 29;280(30):27914-23. Epub 2005 May 23. PMID:15911615
Page seeded by OCA on Wed Nov 21 07:33:28 2007
