Conservation of rapid two-state folding in mesophilic, thermophilic and hyperthermophilic cold shock proteins.
The cold shock protein CspB from Bacillus subtilis is only marginally stable, but it folds extremely fast in a simple N reversible U two-state reaction. The corresponding cold shock proteins from the thermophile Bacillus caldolyticus and the hyperthermophile Thermotoga maritima show strongly increased conformational stabilities, but unchanged very fast two-state refolding kinetics. The absence of intermediates in the folding of B. subtilis CspB is thus not a corollary of its low stability. Rather, two-state folding and an unusually native-like activated state of folding seem to be inherent properties of these small all-beta proteins. There is no link between stability and folding rate, and numerous sequence positions exist which can be varied to modulate the stability without affecting the rate and mechanism of folding.
Perl
D
D
Laboratorium für Biochemie, Universität Bayreuth, Germany.
Welker
C
C
Schindler
T
T
Schröder
K
K
Marahiel
M A
MA
Jaenicke
R
R
Schmid
F X
FX
D000595:Amino Acid Sequence; D001407:Bacillus / Q000235:genetics / Q000378:metabolism*; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D003080:Cold Temperature; D004268:DNA-Binding Proteins / Q000737:chemistry; D006089:Gram-Negative Anaerobic Bacteria / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D007700:Kinetics; D008969:Molecular Sequence Data; D017510:Protein Folding; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013816:Thermodynamics
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C077188:cold-shock protein CspB, Bacteria