title: Unusual heme-histidine bond in the active site of a chaperone.
abstract: The heme chaperone CcmE is essential for the delivery of heme to c-type cytochromes. It forms an unusual transient, yet covalent, bond between an essential histidine, H130, and heme. We report on the discovery of the chemical structure of this bond solved by NMR, where the heme vinyl is cross-linked at the beta carbon to the Ndelta1 of H130. As this type of heme linkage has not been described previously in any cytochrome or hemoprotein, it represents a novel type of heme-histidine complex.
authors.affiliation: Laboratory of Physical Chemistry and Institute of Microbiology, ETH Hönggerberg, CH-8093 Zürich, Switzerland.
authors.forename: Donghan
authors.initials: D
authors.lastname: Lee
authors.forename: Konstantin
authors.initials: K
authors.lastname: Pervushin
authors.forename: Daniela
authors.initials: D
authors.lastname: Bischof
authors.forename: Martin
authors.initials: M
authors.lastname: Braun
authors.forename: Linda
authors.initials: L
authors.lastname: Thöny-Meyer
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D006418:Heme / Q000737:chemistry / Q000378:metabolism*; D006420:Hemeproteins / Q000737:chemistry / Q000378:metabolism*; D006639:Histidine / Q000737:chemistry / Q000378:metabolism*; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001426:Bacterial Proteins; D006420:Hemeproteins; D018832:Molecular Chaperones; D006418:Heme; D006639:Histidine