期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1975
卷号：72
期号：4
页码：1254-1257
DOI：10.1073/pnas.72.4.1254
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In previous studies, a cyanogen bromide peptide derived from amino-acid residues 3-92 of beta-galactosidase (EC 3.2.1.23 ; beta-D-galactoside galactohydrolase) was shown to have alpha-donor activity in intracistronic alpha-complementation. We have now isolated the defective beta-galactosidase alpha-acceptor protein from the deletion mutant strain M15 of Escherichia coli and find that it lacks residues 11-41 of betal-galactosidase. This is demonstrated by the isolation and sequence determination of a cyanogen bromide peptide from the M15 protein, which is identical to the corresponding peptide from beta-galactosidase except for the missing amino acids. We conclude that the alpha-donor peptide restores the region missing in the M15 protein.
