A cytoplasmic chaperonin that catalyzes beta-actin folding.
We have isolated a cytoplasmic chaperonin based on its ability to catalyze the folding of denatured beta-actin. The cytoplasmic chaperonin is organized as a multisubunit toroid and requires Mg2+ and ATP for activity. The folding reaction proceeds via the rapid ATP-independent formation of a binary complex, followed by a slower ATP-dependent release of the native product. Electron microscopic observations reveal a striking structural change that occurs upon addition of Mg2+ and ATP. The eukaryotic cytoplasm thus contains a chaperonin that is functionally analagous to its prokaryotic, mitochondrial, and chloroplastic counterparts.
Department of Biochemistry, New York University Medical Center, New York 10016.
Y
Y
Gao
J O
JO
Thomas
R L
RL
Chow
G H
GH
Lee
N J
NJ
Cowan
D000199:Actins / Q000648:ultrastructure*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D018833:Chaperonins; D002645:Chickens; D003593:Cytoplasm / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D066298:In Vitro Techniques; D011487:Protein Conformation; D011506:Proteins / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins
D000199:Actins; D011506:Proteins; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D018833:Chaperonins