000131662 001__ 131662
000131662 005__ 20240219150720.0
000131662 0247_ $$2doi$$a10.1529/biophysj.106.098277
000131662 0248_ $$2sideral$$a90561
000131662 037__ $$aART-2007-90561
000131662 041__ $$aeng
000131662 100__ $$0(orcid)0000-0002-1827-1250$$aGarcia Rubio, Ines
000131662 245__ $$aAxial coordination of heme in ferric CcmE chaperone characterized by EPR spectroscopy.
000131662 260__ $$c2007
000131662 5060_ $$aAccess copy available to the general public$$fUnrestricted
000131662 5203_ $$aIn Escherichia coli cytochrome c maturation requires a set of eight proteins including the heme chaperone CcmE, which binds heme transiently, yet covalently. Several variants of CcmE were purified and analyzed by continuous-wave electron paramagnetic resonance, electron nuclear double resonance, and hyperfine sublevel correlation spectroscopy to investigate the heme axial coordination. Results reveal the presence of a number of coordination environments, two high-spin heme centers with different rhombicities, and at least one low-spin heme center. The low-spin species was shown to be an artifact induced by the presence of available histidines in the vicinity of the iron. Both of the high-spin forms are five-coordinated, and comparison of the spectra of the wild-type CcmE with those of the mutant CcmEY134H proves that the higher-rhombicity form is coordinated by Tyr134. The low-rhombicity (axial) form does not have a histidine residue or a water molecule as an axial ligand. However, we identified exchangeable protons coupled to the iron ion. We propose that the axial form can be coordinated by a carboxyl group of an acidic residue in the flexible domain of the protein. The two species would represent two different conformations of the flexible α-helix domain surrounding the heme. This conformational flexibility confers CcmE special dynamic properties that are certainly important for its function.
000131662 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/
000131662 590__ $$a4.627$$b2007
000131662 591__ $$aBIOPHYSICS$$b10 / 67 = 0.149$$c2007$$dQ1$$eT1
000131662 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000131662 700__ $$aBraun, M.
000131662 700__ $$aGromov, I.
000131662 700__ $$aThony-Meyer, L.
000131662 700__ $$aSchweiger, Arthur
000131662 773__ $$g92, 4 (2007), 1361-1373$$pBiophys. j.$$tBIOPHYSICAL JOURNAL$$x0006-3495
000131662 8564_ $$s404282$$uhttps://zaguan.unizar.es/record/131662/files/texto_completo.pdf$$yVersión publicada
000131662 8564_ $$s3149308$$uhttps://zaguan.unizar.es/record/131662/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000131662 909CO $$ooai:zaguan.unizar.es:131662$$particulos$$pdriver
000131662 951__ $$a2024-02-19-13:22:39
000131662 980__ $$aARTICLE