Crystal structure of constitutively monomeric E. coli Hsp33 mutant with chaperone activity.
Heat shock protein 33 (Hsp33) from Escherichia coli is a redox-regulated molecular chaperone that protects cells from oxidative stress. To understand the molecular basis for the monomer-dimer switch in the functional regulation of E. coli Hsp33, we generated a constitutively monomeric Hsp33 by introducing the Q151E mutation in the dimeric interface and determined its crystal structure. The overall scaffold of the monomeric Hsp33(1-235) (Q151E) mutant is virtually the same as that of the dimeric form, except that there is no domain swapping. The measurement of chaperone activity to thermally denatured luciferase showed that the constitutively monomeric Hsp33 mutant still retains chaperone activity similar to that of wild-type Hsp33(1-235), suggesting that a Hsp33 monomer is sufficient to interact with slowly unfolded substrate.
Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong-Gu, Daejeon, Republic of Korea.
Seung-Wook
SW
Chi
Dae Gwin
DG
Jeong
Joo Rang
JR
Woo
Hye Seon
HS
Lee
Byoung Cheol
BC
Park
Bo Yeon
BY
Kim
Raymond L
RL
Erikson
Seong Eon
SE
Ryu
Seung Jun
SJ
Kim
D019943:Amino Acid Substitution; D019281:Dimerization; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature / Q000009:adverse effects; D007700:Kinetics; D049409:Luciferases, Firefly / Q000737:chemistry; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D050505:Mutant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D029968:Escherichia coli Proteins; C492165:HSP33 protein, E coli; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D050505:Mutant Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D049409:Luciferases, Firefly