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：1970
卷号：65
期号：3
页码：625-632
DOI：10.1073/pnas.65.3.625
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Mutants of Escherichia coli K12 at the capR locus are overproduce capsular polysaccharide, and are derepressed for synthesis of several enzymes involved in capsular polysaccharide synthesis1-3 including GDP-mannose pyrophosphorylase.8 UDP-glucose pyrophosphorylase is also derepressed in a haploid capR9 mucoid mutant. Heterozygous mucoid partial diploids with the capR9 allele on the episome and the wild-type (capR+) allele on the chromosome (F'capR9/capR+) are derepressed for UDP-glucose pyrophosphorylase and GDP-mannose pyrophosphorylase, while the reciprocal nonmucoid heterozygotes (F'capR+/capR9) are repressed for these enzymes. These results provide evidence that the episomal capR allele is dominant with respect to synthesis of these two enzymes.
