1ykg
Solution structure of the flavodoxin-like domain from the Escherichia coli sulfite reductase
Structural highlights
FunctionCYSJ_ECOLI Component of the sulfite reductase complex that catalyzes the 6-electron reduction of sulfite to sulfide. This is one of several activities required for the biosynthesis of L-cysteine from sulfate. The flavoprotein component catalyzes the electron flow from NADPH -> FAD -> FMN to the hemoprotein component.[HAMAP-Rule:MF_01541] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe flavoprotein moiety of Escherichia coli sulfite reductase (SiR-FP) is homologous to electron transfer proteins such as cytochrome-P450 reductase (CPR) or nitric oxide synthase (NOS). We report on the three-dimensional structure of SiR-FP18, the flavodoxin-like domain of SiR-FP, which has been determined by NMR. In the holoenzyme, this domain plays an important role by shuttling electrons from the FAD to the hemoprotein (the beta-subunit). The structure presented here was determined using distance and torsion angle information in combination with residual dipolar couplings determined in two different alignment media. Several protein-FMN NOEs allowed us to place the prosthetic group in its binding pocket. The structure is well-resolved, and (15)N relaxation data indicate that SiR-FP18 is a compact domain. The binding interface with cytochrome c, a nonphysiological electron acceptor, has been determined using chemical shift mapping. Comparison of the SiR-FP18 structure with the corresponding domains from CPR and NOS shows that the fold of the protein core is highly conserved, but the analysis of the electrostatic surfaces reveals significant differences between the three domains. These observations are placed in the physiological context so they can contribute to the understanding of the electron transfer mechanism in the SiR holoenzyme. Solution structure of the sulfite reductase flavodoxin-like domain from Escherichia coli.,Sibille N, Blackledge M, Brutscher B, Coves J, Bersch B Biochemistry. 2005 Jun 28;44(25):9086-95. PMID:15966732[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
