A critical residue in the folding pathway of an integral membrane protein.
Although a number of common diseases are a direct consequence of membrane protein misfolding, studies of membrane protein folding and misfolding lag well behind those of soluble proteins. Here it is shown that an interfacial residue, Tyr16, of the integral membrane protein diacylglycerol kinase (DAGK) plays a critical role in the folding pathway of this protein. Properly folded Y16C exhibits kinetic parameters and stability similar to wild-type DAGK. However, when unfolded and then allowed to spontaneously fold in the presence of model membranes, Y16C exhibits dramatically lower rates and efficiencies of functional assembly compared to the wild-type protein. The Y16C mutant represents a class of mutations which may be commonly found in disease-related membrane proteins.
Nagy
Joanna K
JK
Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106-4970, USA.
Sanders
Charles R
CR
D000595:Amino Acid Sequence; D019852:Diacylglycerol Kinase / Q000737:chemistry / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology; D007700:Kinetics; D008969:Molecular Sequence Data; D017510:Protein Folding; D013816:Thermodynamics
D019852:Diacylglycerol Kinase