Flexibility and plasticity of human centrin 2 binding to the xeroderma pigmentosum group C protein (XPC) from nuclear excision repair.
Human centrin 2 is a component of the nucleotide excision repair system, as a subunit of the heterotrimer including xeroderma pigmentosum group C protein (XPC) and hHR23B. The C-terminal domain of centrin (C-HsCen2) binds strongly a peptide from the XPC protein (P1-XPC: N(847)-R(863)). Here, we characterize the solution Ca(2+)-dependent structural and molecular features of the C-HsCen2 in complex with P1-XPC, mainly using NMR spectroscopy and molecular modeling. The N-terminal half of the peptide, organized as an alpha helix is anchored into a deep hydrophobic cavity of the protein, because of three bulky hydrophobic residues in position 1-4-8 and electrostatic contacts with the centrin helix E. Investigation of the whole centrin interactions shows that the N-terminal domain of the protein is not involved in the complex formation and is structurally independent from the peptide-bound C-terminal domain. The complex may exist in three different binding conformations corresponding to zero, one, and two Ca(2+)-bound states, which may exchange with various rates and have distinct structural stability. The various features of the intermolecular interaction presented here constitute a centrin-specific mode for the target binding.
Integrative Imaging Unit, INSERM U759/Institut Curie-Recherche, Centre Universitaire Paris-Sud, Bâtiment 112, 91405 Orsay Cedex, France.
Ao
A
Yang
Simona
S
Miron
Liliane
L
Mouawad
Patricia
P
Duchambon
Yves
Y
Blouquit
Constantin T
CT
Craescu
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002118:Calcium / Q000378:metabolism; 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; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013696:Temperature; D014983:Xeroderma Pigmentosum / Q000737:chemistry / Q000378:metabolism*
C472752:CETN2 protein, human; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; C086984:XPC protein, human; D002118:Calcium