1e7p: Difference between revisions

Quinol:fumarate reductase (QFR) is a membrane protein complex that couples, the reduction of fumarate to succinate to the oxidation of quinol to, quinone. Previously, the crystal structure of QFR from Wolinella, succinogenes was determined based on two different crystal forms, and the, site of fumarate binding in the flavoprotein subunit A of the enzyme was, located between the FAD-binding domain and the capping domain [Lancaster, C.R.D., Kroger, A., Auer, M., & Michel, H. (1999) Nature 402, 377--385]., Here we describe the structure of W. succinogenes QFR based on a third, crystal form and refined at 3.1 A resolution. Compared with the previous, crystal forms, the capping domain is rotated in this structure by, approximately 14 degrees relative to the FAD-binding domain. As a, consequence, the topology of the dicarboxylate binding site is much more, similar to those of membrane-bound and soluble fumarate reductase enzymes, from other organisms than to that found in the previous crystal forms of, W. succinogenes QFR. This and the effects of the replacement of Arg A301, by Glu or Lys by site-directed mutagenesis strongly support a common, mechanism for fumarate reduction in this superfamily of enzymes.

1E7P is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Wolinella_succinogenes Wolinella succinogenes] with NA, HEM, FES, F3S, SF4, FAD, MLA and LMT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Succinate_dehydrogenase Succinate dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.3.99.1 1.3.99.1] Structure known Active Sites: FA1, FA2, FA3, FA4, FS1, FS2, FS3, FS4, FS5, FS6, FS7, FS8, FS9, FSA, FSB, FSC, HE1, HE2, HE3 and HE4. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1E7P OCA].  

''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov  5 12:58:06 2007''