PDBsum entry 2obh

Cell cycle

PDB id: 2obh

Contents

Protein chains

143 a.a. *

17 a.a. *

18 a.a. *

Metals

_CA ×4

Waters ×384

* Residue conservation analysis

PDB id:

2obh

Name:

Cell cycle

Title:

Centrin-xpc peptide

Structure:

Centrin-2. Chain: a, b. Fragment: hscen2 ( residues: 26-168). Synonym: caltractin isoform 1. Engineered: yes. DNA-repair protein complementing xp-c cells. Chain: c, d. Fragment: xpc fragment (residues: 847-863). Synonym: xeroderma pigmentosum group c-complementing protein, p125.

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: cetn2, calt, cen2. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008. Synthetic: yes. Other_details: this sequence occurs in homo sapiens

Resolution:

1.80Å R-factor: 0.205 R-free: 0.265

Authors:

J.B.Charbonnier

Key ref:

J.B.Charbonnier et al. (2007). Structural, thermodynamic, and cellular characterization of human centrin 2 interaction with xeroderma pigmentosum group C protein. J Mol Biol, 373, 1032-1046. PubMed id: 17897675 DOI: 10.1016/j.jmb.2007.08.046

Date:

19-Dec-06 Release date: 09-Oct-07

Protein chains

P41208  (CETN2_HUMAN) -  Centrin-2 from Homo sapiens

Seq: 172 a.a.

Struc: 143 a.a.

Protein chain

Q01831  (XPC_HUMAN) -  DNA repair protein complementing XP-C cells from Homo sapiens

Seq: 940 a.a.

Struc: 16 a.a.

Protein chain

Q01831  (XPC_HUMAN) -  DNA repair protein complementing XP-C cells from Homo sapiens

Seq: 940 a.a.

Struc: 17 a.a.

DOI no: 10.1016/j.jmb.2007.08.046

J Mol Biol 373:1032-1046 (2007)

PubMed id: 17897675

Structural, thermodynamic, and cellular characterization of human centrin 2 interaction with xeroderma pigmentosum group C protein.

J.B.Charbonnier, E.Renaud, S.Miron, M.H.Le Du, Y.Blouquit, P.Duchambon, P.Christova, A.Shosheva, T.Rose, J.F.Angulo, C.T.Craescu.

ABSTRACT

Human centrin 2 (HsCen2), an EF-hand calcium binding protein, plays a regulatory role in the DNA damage recognition during the first steps of the nucleotide excision repair. This biological action is mediated by the binding to a short fragment (N847-R863) from the C-terminal region of xeroderma pigmentosum group C (XPC) protein. This work presents a detailed structural and energetic characterization of the HsCen2/XPC interaction. Using a truncated form of HsCen2 we obtained a high resolution (1.8 A) X-ray structure of the complex with the peptide N847-R863 from XPC. Structural and thermodynamic analysis of the interface revealed the existence of both electrostatic and apolar inter-molecular interactions, but the binding energy is mainly determined by the burial of apolar bulky side-chains into the hydrophobic pocket of the HsCen2 C-terminal domain. Binding studies with various peptide variants showed that XPC residues W848 and L851 constitute the critical anchoring side-chains. This enabled us to define a minimal centrin binding peptide variant of five residues, which accounts for about 75% of the total free energy of interaction between the two proteins. Immunofluorescence imaging in HeLa cells demonstrated that HsCen2 binding to the integral XPC protein may be observed in living cells, and is determined by the same interface residues identified in the X-ray structure of the complex. Overexpression of XPC perturbs the cellular distribution of HsCen2, by inducing a translocation of centrin molecules from the cytoplasm to the nucleus. The present data confirm that the in vitro structural features of the centrin/XPC peptide complex are highly relevant to the cellular context.

Selected figure(s)

Figure 2.
Figure 2. Crystal structure of the complex ΔN25-HsCen2/P17-XPC. (a) Global view of the two ΔN25-HsCen2/P17-XPC complexes observed in the asymmetric unit. The centrin molecules are represented in green and orange ribbons. The two bound P17-XPC peptides are shown in dark blue and red ribbons. The calcium ions present in the C-terminal binding sites of centrin molecules are represented as magenta (site IV) and grey (site III) balls. (b) Zoom of the centrin/peptide interaction and position of this interface relative to the Ca^2+ binding sites. The orientation of the complexes in (a) and (b) is the same. (c) and (d) Electron density maps around the Ca^2+ binding sites IV (c) and III (d). 2F[o]–F[c] maps contoured at 2σ are represented.

Figure 3.
Figure 3. (a) The B factors of the centrin and peptide C^α atoms in the complex ΔN25-HsCen2/P17-XPC, plotted against the residue number. Data for the two centrin and two peptide molecules in the crystallographic asymmetric unit (black and red) are compared with the corresponding factors in the structure by Thompson et al.^18 (blue and green). The helical fragments in the protein are indicated by the shaded areas. The empty and filled green circles indicate the free and bound Ca^2+ sites, respectively. (b) The Ramachadran plot of the complex dimer; 95.5% and 4.5% of the residues were found in the most favored and additional allowed regions, respectively.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2007, 373, 1032-1046) copyright 2007.

Figures were selected by an automated process.