Identification of neighbouring proteins by cross-linking of intact 70 S ribosomes from Escherichia coli.
70 S ribosomes from Escherichia coli have been reacted with the bifunctional reagent 1,4-phenyldiglyoxal under near physiological conditions. As a result of the cross-linking reaction a number of high-molecular-weight protein fractions with altered electrophoretic mobility could be isolated. A new chemical procedure has been introduced to reverse the cross-links between proteins at least partially. The cleavage reaction did not affect the gel electrophoretic mobility of the proteins. Thus a direct identification of cross-linked proteins using one- or two-dimensional gels was made possible. Two protein trimers, S3-S4-S5 and L1-S4-S5, as well as five protein dimers, S3-S4, L6-L7/12, L10-L7/12, S9-L19 and L18-L19 could be identified as close neighbours in the E. coli 70 S ribosome. The protein pairs S9-L19 and L18-L19 had previously not been identified as near neighbours using cross-linking studies.
D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000648:ultrastructure*; D008970:Molecular Weight; D012269:Ribosomal Proteins; D012270:Ribosomes / Q000648:ultrastructure*
D003432:Cross-Linking Reagents; D012269:Ribosomal Proteins