1l5y
From Proteopedia
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CRYSTAL STRUCTURE OF MG2+ / BEF3-BOUND RECEIVER DOMAIN OF SINORHIZOBIUM MELILOTI DCTD
Overview
A Crystallogral structure is described for the Mg2+-BeF3--bound receiver, domain of Sinorhizobium meliloti DctD bearing amino acid substitution, E121K. Differences between the apo- and ligand-bound active sites are, similar to those reported for other receiver domains. However, the off and, on states of the DctD receiver domain are characterized by dramatically, different dimeric structures, which supports the following hypothesis of, signal transduction. In the off state, the receiver domain and coiled-coil, linker form a dimer that inhibits oligomerization of the AAA+ ATPase, domain. In this conformation, the receiver domain cannot be phosphorylated, or bind Mg2+ and BeF3-. Instead, these modifications stabilize an, alternative dimeric conformation that repositions the subunits by, approximately 20 A, thus replacing the a4-b5-a5 interface with an a4-b5, interface. Reoriented receiver domains permit the ATPase domain to, oligomerize and stimulate open complex formation by the s54 form of RNA, polymerase. NtrC, which shares 38% sequence identity with DctD, works, differently. Its activated receiver domain must facilitate oligomerization, of its ATPase domain. Significant differences exist in the signaling, surfaces of the DctD and NtrC receiver domains that may help explain how, triggering the common two-component switch can variously regulate assembly, of a AAA+ ATPase domain.
About this Structure
1L5Y is a Single protein structure of sequence from Sinorhizobium meliloti with MG, SO4, BEF, BF2, BF4 and GOL as ligands. Full crystallographic information is available from OCA.
Reference
Two-component signaling in the AAA + ATPase DctD: binding Mg2+ and BeF3- selects between alternate dimeric states of the receiver domain., Park S, Meyer M, Jones AD, Yennawar HP, Yennawar NH, Nixon BT, FASEB J. 2002 Dec;16(14):1964-6. Epub 2002 Oct 4. PMID:12368235
Page seeded by OCA on Tue Nov 20 20:17:56 2007
