Structure-function analysis of the heat shock factor-binding protein reveals a protein composed solely of a highly conserved and dynamic coiled-coil trimerization domain

被引:37
作者
Tai, LJ
McFall, SM
Huang, K
Demeler, B
Fox, SG
Brubaker, K
Radhakrishnan, I [1 ]
Morimoto, RI
机构
[1] Northwestern Univ, Dept Biochem, Evanston, IL 60208 USA
[2] Northwestern Univ, Dept Mol Biol, Evanston, IL 60208 USA
[3] Northwestern Univ, Dept Cell Biol, Evanston, IL 60208 USA
[4] Northwestern Univ, Rice Inst Biomed Res, Evanston, IL 60208 USA
[5] Northwestern Univ, Struct Biol NMR Facil, Evanston, IL 60208 USA
[6] Univ Texas, Hlth Sci Ctr, Dept Biochem, San Antonio, TX 78284 USA
关键词
D O I
10.1074/jbc.M108604200
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Heat shock factor-binding protein (HSBP) I is a small, evolutionarily conserved protein originally identified in a yeast two-hybrid screen using the trimerization domain of heat shock factor (HSF) I as the bait. Similar in size to HSF1 trimerization domain, human HSBP1 contains two arrays of hydrophobic heptad repeats (designated HR-N and HR-C) characteristic of coiled-coil proteins. Proteins of the HSBP family are relatively small (< 100 residues), comprising solely a putative coiled-coil oligomerization domain without any other readily recognizable structural or functional motif. Our biophysical and biochemical characterization of human HSBP1 reveals a cooperatively folded protein with high a-helical content and moderate stability. NMR analyses reveal a single continuous helix encompassing both HR-N and HR-C in the highly conserved central region, whereas the less conserved carboxyl terminus is unstructured and accessible to proteases. Unlike previously characterized coiled-coils, backbone N-15 relaxation measurements implicate motional processes on the millisecond time scale in the coiled-coil region. Analytical ultracentrifugation and native PAGE studies indicate that HSBP1 is predominantly trimeric over a wide concentration range. NMR analyses suggest a rotationally symmetric trimer. Because the highly conserved hydrophobic heptad repeats extend over 60% of HSBP1, we propose that HSBP most likely regulates the function of other proteins through coiled-coil interactions.
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页码:735 / 745
页数:11
相关论文
共 72 条
[1]   Gapped BLAST and PSI-BLAST: a new generation of protein database search programs [J].
Altschul, SF ;
Madden, TL ;
Schaffer, AA ;
Zhang, JH ;
Zhang, Z ;
Miller, W ;
Lipman, DJ .
NUCLEIC ACIDS RESEARCH, 1997, 25 (17) :3389-3402
[2]  
AUSUBEL FM, 1998, CURRENT PROTOCOLS MO, V2
[3]  
AUSUBEL FM, 1998, CURRENT PROTOCOLS MO, V4
[4]   Supercoiled protein motifs:: The collagen triple-helix and the α-helical coiled coil [J].
Beck, K ;
Brodsky, B .
JOURNAL OF STRUCTURAL BIOLOGY, 1998, 122 (1-2) :17-29
[5]   Temperature dependence of intramolecular dynamics of the basic leucine zipper of GCN4: Implications for the entropy of association with DNA [J].
Bracken, C ;
Carr, PA ;
Cavanagh, J ;
Palmer, AG .
JOURNAL OF MOLECULAR BIOLOGY, 1999, 285 (05) :2133-2146
[6]  
Brown JH, 1996, PROTEINS, V26, P134
[7]   An efficient and cost-effective isotope labeling protocol for proteins expressed in Escherichia coli [J].
Cai, ML ;
Huang, Y ;
Sakaguchi, K ;
Clore, GM ;
Gronenborn, AM ;
Craigie, R .
JOURNAL OF BIOMOLECULAR NMR, 1998, 11 (01) :97-102
[8]   (VASOPRESSIN-H-3 BINDING TO ISOLATED RAT HEPATOCYTES AND LIVER MEMBRANES - REGULATION BY GTP AND RELATION TO GLYCOGEN-PHOSPHORYLASE ACTIVATION [J].
CANTAU, B ;
KEPPENS, S ;
DEWULF, H ;
JARD, S .
JOURNAL OF RECEPTOR RESEARCH, 1980, 1 (02) :137-168
[9]  
CANTOR CR, 1980, BIOPHYSICAL CHEM, V2
[10]  
Carruthers LM, 2000, METHOD ENZYMOL, V321, P66