Probing the role of the conserved beta-II turn Pro-76/Gly-77 of mitochondrial cytochrome c. Export

@article{citeulike:6017070, abstract = {The loop segment comprising residues 70-84 in mitochondrial cytochrome c serves to direct the polypeptide backbone to permit the functionally required heme Fe - S (Met-80) co-ordination. The primary sequence here is highly conserved, which is something rarely observed in surface loop segments and suggests that its purpose is more complex than its obvious structural role. The beta-II turn formed by Pro-76 and Gly-77 is postulated to be key to the redirection of the peptide backbone required to execute the loop. We assessed the importance of Pro-76 and Gly-77 by mutating 1 or both of these residues to alanine such that the range of allowable dihedral angles was altered, and this resulted in significant changes in physicochemical properties and biological activities. We observed structural perturbations using circular dichroism spectroscopy and thermal denaturation studies. Based on these changes, we propose that the Pro-76/Gly-77 beta-II turn precisely orients the 70s loop, not only to maintain the backbone orientation required for the formation of the axial heme ligand, but also to provide a complementary surface to physiological partners.}, author = {Black, Karen M. and Wallace, Carmichael J.}, citeulike-article-id = {6017070}, citeulike-linkout-0 = {http://dx.doi.org/10.1139/o07-049}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/17612631}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=17612631}, doi = {10.1139/o07-049}, issn = {0829-8211}, journal = {Biochemistry and cell biology = Biochimie et biologie cellulaire}, keywords = {alanine, angle, black07pdf, c, cytochrome, dihedral, modulation}, month = {June}, number = {3}, pages = {366--374}, posted-at = {2009-10-27 23:00:40}, priority = {2}, title = {Probing the role of the conserved beta-II turn Pro-76/Gly-77 of mitochondrial cytochrome c.}, url = {http://dx.doi.org/10.1139/o07-049}, volume = {85}, year = {2007} }

TY - JOUR ID - citeulike:6017070 L3 - citeulike-article-id:6017070 N2 - The loop segment comprising residues 70-84 in mitochondrial cytochrome c serves to direct the polypeptide backbone to permit the functionally required heme Fe - S (Met-80) co-ordination. The primary sequence here is highly conserved, which is something rarely observed in surface loop segments and suggests that its purpose is more complex than its obvious structural role. The beta-II turn formed by Pro-76 and Gly-77 is postulated to be key to the redirection of the peptide backbone required to execute the loop. We assessed the importance of Pro-76 and Gly-77 by mutating 1 or both of these residues to alanine such that the range of allowable dihedral angles was altered, and this resulted in significant changes in physicochemical properties and biological activities. We observed structural perturbations using circular dichroism spectroscopy and thermal denaturation studies. Based on these changes, we propose that the Pro-76/Gly-77 beta-II turn precisely orients the 70s loop, not only to maintain the backbone orientation required for the formation of the axial heme ligand, but also to provide a complementary surface to physiological partners. IS - 3 JF - Biochemistry and cell biology = Biochimie et biologie cellulaire SN - 0829-8211 EP - 374 TI - Probing the role of the conserved beta-II turn Pro-76/Gly-77 of mitochondrial cytochrome c. VL - 85 SP - 366 KW - alanine KW - angle KW - black07pdf KW - c KW - cytochrome KW - dihedral KW - modulation AU - Black, Karen AU - Wallace, Carmichael PY - 2007/06// UR - http://dx.doi.org/10.1139/o07-049 ER -