2a3l

From Proteopedia

Revision as of 13:44, 20 March 2008

X-Ray Structure of Adenosine 5'-Monophosphate Deaminase from Arabidopsis Thaliana in Complex with Coformycin 5'-Phosphate

Overview

Embryonic factor 1 (FAC1) is one of the earliest expressed plant genes and encodes an AMP deaminase (AMPD), which is also an identified herbicide target. This report identifies an N-terminal transmembrane domain in Arabidopsis FAC1, explores subcellular fractionation, and presents a 3.3-A globular catalytic domain x-ray crystal structure with a bound herbicide-based transition state inhibitor that provides the first glimpse of a complete AMPD active site. FAC1 contains an (alpha/beta)(8)-barrel characterized by loops in place of strands 5 and 6 that places it in a small subset of the amidohydrolase superfamily with imperfect folds. Unlike tetrameric animal orthologs, FAC1 is a dimer and each subunit contains an exposed Walker A motif that may be involved in the dramatic combined K(m) (25-80-fold lower) and V(max) (5-6-fold higher) activation by ATP. Normal mode analysis predicts a hinge motion that flattens basic surfaces on each monomer that flank the dimer interface, which suggests a reversible association between the FAC1 globular catalytic domain and intracellular membranes, with N-terminal transmembrane and disordered linker regions serving as the anchor and attachment to the globular catalytic domain, respectively.

About this Structure

2A3L is a Single protein structure of sequence from Arabidopsis thaliana. Full crystallographic information is available from OCA.

Reference

Membrane association, mechanism of action, and structure of Arabidopsis embryonic factor 1 (FAC1)., Han BW, Bingman CA, Mahnke DK, Bannen RM, Bednarek SY, Sabina RL, Phillips GN Jr, J Biol Chem. 2006 May 26;281(21):14939-47. Epub 2006 Mar 16. PMID:16543243

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