title: Site-directed mutation on the only universally conserved residue Leu122 of small heat shock protein Hsp16.3.
abstract: Hsp16.3 from Mycobacterium tuberculosis belongs to the small heat shock protein family and has chaperone-like activity in vitro. The only universally conserved hydrophobic residue Leu122 was substituted by Val and Ala, respectively. The mutations on the Leu122 of Hsp16.3 have resulted in much lower structural stability in vivo and in vitro. Both mutant proteins exhibited much weaker chaperone-like activities than the Hsp16.3 WT under heat shock conditions. Taken together, the highly hydrophobic residue L122 of Hsp16.3 was suggested to play a very important role in maintaining not only the structural stability but also the chaperone-like activity.
authors.affiliation: Institute of Biochemistry and Molecular Biology, Tsinghua University, Beijing, 100084, People's Republic of China.
authors.forename: Q
authors.initials: Q
authors.lastname: Mao
authors.forename: Z
authors.initials: Z
authors.lastname: Chang
mesh_terms: D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018833:Chaperonins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D006358:Hot Temperature; D007930:Leucine / Q000737:chemistry; D016297:Mutagenesis, Site-Directed; D009169:Mycobacterium tuberculosis / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C431133:Hsp16.3 protein, Mycobacterium tuberculosis; D011994:Recombinant Proteins; D018833:Chaperonins; D007930:Leucine