Membrane association, mechanism of action, and structure of Arabidopsis embryonic factor 1 (FAC1).Han, B.W., Bingman, C.A., Mahnke, D.K., Bannen, R.M., Bednarek, S.Y., Sabina, R.L., Phillips, G.N.
(2006) J.Biol.Chem. 281: 14939-14947
- PubMed: 16543243
- DOI: 10.1074/jbc.M513009200
- PubMed Abstract:
- Crystallization and preliminary X-ray crystallographic analysis of adenosine 5'-monophosphate deaminase (AMPD) from Arabidopsis thaliana in complex with coformycin 5'-phosphate
Han, B.W.,Bingham, C.A.,Mahnke, D.K.,Sabina, R.L.,Phillips Jr., G.N.
(2005) Acta Crystallogr.,Sect.F 61: 740
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 subcellu ...
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.
Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA.