title: The structure of the human centrin 2-xeroderma pigmentosum group C protein complex.
abstract: Human centrin-2 plays a key role in centrosome function and stimulates nucleotide excision repair by binding to the xeroderma pigmentosum group C protein. To determine the structure of human centrin-2 and to develop an understanding of molecular interactions between centrin and xeroderma pigmentosum group C protein, we characterized the crystal structure of calcium-loaded full-length centrin-2 complexed with a xeroderma pigmentosum group C peptide. Our structure shows that the carboxyl-terminal domain of centrin-2 binds this peptide and two calcium atoms, whereas the amino-terminal lobe is in a closed conformation positioned distantly by an ordered alpha-helical linker. A stretch of the amino-terminal domain unique to centrins appears disordered. Two xeroderma pigmentosum group C peptides both bound to centrin-2 also interact to form an alpha-helical coiled-coil. The interface between centrin-2 and each peptide is predominantly nonpolar, and key hydrophobic residues of XPC have been identified that lead us to propose a novel binding motif for centrin.
authors.affiliation: Department of Physiology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA. thompson.james@mayo.edu
authors.forename: James R
authors.initials: JR
authors.lastname: Thompson
authors.forename: Zachary C
authors.initials: ZC
authors.lastname: Ryan
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Salisbury
authors.forename: Rajiv
authors.initials: R
authors.lastname: Kumar
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001665:Binding Sites; D002118:Calcium; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D014983:Xeroderma Pigmentosum / Q000378:metabolism
chemical_list: C472752:CETN2 protein, human; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D010446:Peptide Fragments; C086984:XPC protein, human; D002118:Calcium