3d31
ModBC from Methanosarcina acetivorans
OverviewOverview
Transport across cellular membranes is an essential process that is catalyzed by diverse membrane transport proteins. The turnover rates of certain transporters are inhibited by their substrates in a process termed trans-inhibition, whose structural basis is poorly understood. Here we present the crystal structure of a molybdate/tungstate ABC transporter (ModBC) from Methanosarcina acetivorans in a trans-inhibited state. The regulatory domains of the nucleotide-binding subunits are in close contact and provide two oxyanion binding pockets at the shared interface. By specifically binding to these pockets, molybdate or tungstate prevent ATPase activity and lock the transporter in an inward-facing conformation, with the catalytic motifs of the nucleotide-binding domains separated. This allosteric effect prevents the transporter from switching between the inward-facing and the outward-facing states, thus interfering with the alternating access and release mechanism.
About this StructureAbout this Structure
3D31 is a Protein complex structure of sequences from Methanosarcina acetivorans. Full crystallographic information is available from OCA.
ReferenceReference
Structural Basis of Trans-Inhibition in a Molybdate/tungstate ABC Transporter., Gerber S, Comellas-Bigler M, Goetz BA, Locher KP, Science. 2008 May 29;. PMID:18511655 Page seeded by OCA on Wed Jun 11 10:51:13 2008