Suárez Rendueles P, Wolf D H
J Bacteriol. 1987 Sep;169(9):4041-8. doi: 10.1128/jb.169.9.4041-4048.1987.
Mutants of Saccharomyces cerevisiae lacking dipeptidyl aminopeptidase yscV were isolated from a strain already defective in dipeptidyl aminopeptidase yscIV, an enzyme with overlapping substrate specificity. The mutants were identified by a staining technique with the chromogenic substrate Ala-Pro-4-methoxy-beta-naphthylamide to screen colonies for the absence of the enzyme. One of the mutants had a thermolabile activity, indicating that it contained a structural gene mutation. The 53 mutants analyzed fell into one complementation group that corresponded to the yscV structural gene, DAP2. The defect segregated 2:2 in meiotic tetrads, indicating a single chromosomal gene mutation, which was shown to be recessive. Diploids heterozygous for DAP2 displayed gene dosage effects with respect to yscV enzyme activity. The absence of dipeptidyl aminopeptidase yscV or the combined loss of both dipeptidyl aminopeptidases yscIV and yscV did not affect mitotic growth under rich or poor growth conditions. In contrast to the dipeptidyl aminopeptidase yscIV lesion (ste13), which leads to alpha sterility because strains secrete incompletely processed forms of the alpha-factor pheromone, the dipeptidyl aminopeptidase yscV lesion did not affect mating, and strains produced fully active alpha-factor pheromone. dap2 mutants did not show any obvious phenotype under a variety of conditions tested.
从已经缺乏二肽基氨肽酶yscIV（一种底物特异性重叠的酶）的酿酒酵母菌株中分离出缺乏二肽基氨肽酶yscV的突变体。通过用生色底物丙氨酸 - 脯氨酸 - 4 - 甲氧基 - β - 萘酰胺的染色技术鉴定突变体，以筛选缺乏该酶的菌落。其中一个突变体具有热不稳定活性，表明它含有一个结构基因突变。分析的53个突变体属于一个对应于yscV结构基因DAP2的互补群。该缺陷在减数分裂四分体中以2:2分离，表明是单个染色体基因突变，且该突变显示为隐性。DAP2杂合的二倍体在yscV酶活性方面表现出基因剂量效应。缺乏二肽基氨肽酶yscV或同时缺乏二肽基氨肽酶yscIV和yscV在丰富或贫乏生长条件下均不影响有丝分裂生长。与导致α不育的二肽基氨肽酶yscIV损伤（ste13）不同，因为菌株分泌未完全加工形式的α因子信息素，而二肽基氨肽酶yscV损伤不影响交配，且菌株产生完全有活性的α因子信息素。在各种测试条件下，dap2突变体均未表现出任何明显的表型。
