Purification and functional characterization of a chaperone from Methanococcus jannaschii.
A chaperone from Methanococcus jannaschii has been purified to homogeneity with a single chromatographic step. The chaperone was identified and characterized using activity assays for characteristic chaperone abilities. The M. jannaschii chaperone binds unfolded proteins, protects proteins against heat-induced aggregation, and has a strongly temperature dependent ATPase activity. The chaperone has also been shown to inhibit the spontaneous refolding of a mesophilic protein at low temperatures. The purified chaperone complex has a M(r) of about 1,000,000 and consists of a single type of subunit with an approximate M(r) of 60,000. Analysis of partial sequence data reveals that this chaperone is the predicted protein product of the previously identified chaperonin gene in M. jannaschii (BULT et al., 1996). To our knowledge, this is the first functional characterization of a chaperone from a methanogen.
Department of Chemical Engineering, University of Illinois, Urbana, USA.
J M
JM
Kowalski
R M
RM
Kelly
J
J
Konisky
D S
DS
Clark
K D
KD
Wittrup
D000251:Adenosine Triphosphatases / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D019843:Archaeal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000502:physiology*; D015153:Blotting, Western; D002850:Chromatography, Gel; D003488:Cyanogen Bromide / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D019848:Gene Expression Regulation, Archaeal; D006041:Goats; D008156:Luciferases / Q000737:chemistry / Q000276:immunology; D008163:Luminescent Measurements; D017017:Methanococcus / Q000737:chemistry*; D018832:Molecular Chaperones / Q000737:chemistry / Q000302:isolation & purification / Q000502:physiology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017510:Protein Folding; D011817:Rabbits; D016415:Sequence Alignment; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid
D019843:Archaeal Proteins; D018832:Molecular Chaperones; D008156:Luciferases; D000251:Adenosine Triphosphatases; D003488:Cyanogen Bromide