1kjq

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spinqualitylabelsall models 1kjq, resolution 1.05Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of glycinamide ribonucleotide transformylase in complex with Mg-ADP

Overview

PurT-encoded glycinamide ribonucleotide transformylase, or PurT, transformylase, functions in purine biosynthesis by catalyzing the, formylation of glycinamide ribonucleotide through a catalytic mechanism, requiring Mg(2+)ATP and formate. From previous x-ray diffraction analyses, it has been demonstrated that PurT transformylase from Escherichia coli, belongs to the ATP-grasp superfamily of enzymes, which are characterized, by three structural motifs referred to as the A-, B-, and C-domains. In, all of the ATP-grasp enzymes studied to date, the adenosine nucleotide, ligands are invariably wedged between the B- and C-domains, and in some, cases, such as biotin carboxylase and carbamoyl phosphate synthetase, the, B-domains move significantly upon nucleotide binding. Here we present a, systematic and high-resolution structural investigation of PurT, transformylase complexed with various adenosine nucleotides or nucleotide, analogs including Mg(2+)ATP, Mg(2+)-5'-adenylylimidodiphosphate, Mg(2+)-beta,gamma-methyleneadenosine 5'-triphosphate, Mg(2+)ATPgammaS, or, Mg(2+)ADP. Taken together, these studies indicate that the conformation of, the so-called "T-loop," delineated by Lys-155 to Gln-165, is highly, sensitive to the chemical identity of the nucleotide situated in the, binding pocket. This sensitivity to nucleotide identity is in sharp, contrast to that observed for the "P-loop"-containing enzymes, in which, the conformation of the binding motif is virtually unchanged in the, presence or absence of nucleotides.

About this Structure

1KJQ is a Single protein structure of sequence from Escherichia coli with MG, NA, CL, ADP, MPO and EDO as ligands. Full crystallographic information is available from OCA.

Reference

PurT-encoded glycinamide ribonucleotide transformylase. Accommodation of adenosine nucleotide analogs within the active site., Thoden JB, Firestine SM, Benkovic SJ, Holden HM, J Biol Chem. 2002 Jun 28;277(26):23898-908. Epub 2002 Apr 12. PMID:11953435

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