説明
Publisher Summary This chapter discusses the genome of Mycoplasma capricolum. The simplest way to estimate the approximate number of genes encoded in the genome is to count the number of the gene products in the cell. The entire protein content of M. capricolum was analyzed by two-dimensional polyacrylamide gel electrophoresis of O’Farrell. Acidic proteins were separated using isoelectrofocusing gels for the first dimension with a gradient of pH 5-7 and basic proteins with a gradient of pH 7-9. A total of about 350 spots, 200 in the acidic and 150 in the basic range, was detected. Under the same conditions, the numbers of the whole cell proteins of E. coli and B. subtilis are about 1,100. The results indicate that at least 350 genes for proteins are expressed in the growing M. capricolum cells. The average molecular weight of proteins is about 40,000. The number of expressed genes would represent roughly the number of genes for proteins encoded in the genome. The small number of the protein spots is consistent with the view that mycoplasmas contain only a limited number of the genes necessary for growth and that most, if not all, of them must be expressed in the growing cells.