TY - JOUR
T1 - Biophysical characterizations of human mitochondrial transcription factor A and its binding to tumor suppressor p53
AU - Wong, Tuck Seng
AU - Rajagopalan, Sridharan
AU - Freund, Stefan M.
AU - Rutherford, Trevor J.
AU - Andreeva, Antonina
AU - Townsley, Fiona M.
AU - Petrovich, Miriana
AU - Fersht, Alan R.
N1 - Funding Information:
The European Union FP6 Proteomage (to A.R.F. and T.S.W.); MRC Career Development Fellowship (to T.S.W.). Funding for open access charge: Medical Research Council, UK.
PY - 2009/9/15
Y1 - 2009/9/15
N2 - Human mitochondrial transcription factor A (TFAM) is a multi-functional protein, involved in different aspects of maintaining mitochondrial genome integrity. In this report, we characterized TFAM and its interaction with tumor suppressor p53 using various biophysical methods. DNA-free TFAM is a thermally unstable protein that is in equilibrium between monomers and dimers. Self-association of TFAM is modulated by its basic C-terminal tail. The DNA-binding ability of TFAM is mainly contributed by its first HMG-box, while the second HMG-box has low-DNA-binding capability. We also obtained backbone resonance assignments from the NMR spectra of both HMG-boxes of TFAM. TFAM binds primarily to the N-terminal transactivation domain of p53, with a Kd of 1.95 ± 0.19 μM. The C-terminal regulatory domain of p53 provides a secondary binding site for TFAM. The TFAM-p53-binding interface involves both TAD1 and TAD2 sub-domains of p53. Helices α1 and α2 of the HMG-box constitute the main p53-binding region. Since both TFAM and p53 binds preferentially to distorted DNA, the TFAM-p53 interaction is implicated in DNA damage and repair. In addition, the DNA-binding mechanism of TFAM and biological relevance of the TFAM-p53 interaction are discussed.
AB - Human mitochondrial transcription factor A (TFAM) is a multi-functional protein, involved in different aspects of maintaining mitochondrial genome integrity. In this report, we characterized TFAM and its interaction with tumor suppressor p53 using various biophysical methods. DNA-free TFAM is a thermally unstable protein that is in equilibrium between monomers and dimers. Self-association of TFAM is modulated by its basic C-terminal tail. The DNA-binding ability of TFAM is mainly contributed by its first HMG-box, while the second HMG-box has low-DNA-binding capability. We also obtained backbone resonance assignments from the NMR spectra of both HMG-boxes of TFAM. TFAM binds primarily to the N-terminal transactivation domain of p53, with a Kd of 1.95 ± 0.19 μM. The C-terminal regulatory domain of p53 provides a secondary binding site for TFAM. The TFAM-p53-binding interface involves both TAD1 and TAD2 sub-domains of p53. Helices α1 and α2 of the HMG-box constitute the main p53-binding region. Since both TFAM and p53 binds preferentially to distorted DNA, the TFAM-p53 interaction is implicated in DNA damage and repair. In addition, the DNA-binding mechanism of TFAM and biological relevance of the TFAM-p53 interaction are discussed.
UR - http://www.scopus.com/inward/record.url?scp=73349095758&partnerID=8YFLogxK
U2 - 10.1093/nar/gkp750
DO - 10.1093/nar/gkp750
M3 - Article
C2 - 19755502
AN - SCOPUS:73349095758
SN - 0305-1048
VL - 37
SP - 6765
EP - 6783
JO - Nucleic Acids Research
JF - Nucleic Acids Research
IS - 20
M1 - gkp750
ER -