NMR structure of the heme chaperone CcmE reveals a novel functional motif.
The concept of metal chaperones involves transient binding of metallic cofactors by specific proteins for delivery to enzymes in which they function. Metal chaperones thus provide a protective, as well as a transport, function. We report the first structure of a heme chaperone, CcmE, which comprises these two functions. We propose that the covalent attachment of heme to an exposed histidine occurs after heme binding at the surface of a rigid molecule with a flexible C-terminal domain. CcmE belongs to a family of proteins with a specific fold, which all share a function in delivery of specific molecular cargo.
Enggist
Elisabeth
E
Institut für Mikrobiologie, Eidgenössische Technische Hochschule, Zürich, Switzerland.
Thöny-Meyer
Linda
L
Güntert
Peter
P
Pervushin
Konstantin
K
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D029968:Escherichia coli Proteins; D006418:Heme / Q000378:metabolism; D006420:Hemeproteins / Q000737:chemistry* / Q000378:metabolism; D006639:Histidine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013053:Spectrophotometry
D001425:Bacterial Outer Membrane Proteins; C115384:CcmE protein, E coli; D029968:Escherichia coli Proteins; D006420:Hemeproteins; D006418:Heme; D006639:Histidine