Solioz M, Schatz G
J Biol Chem. 1979 Oct 10;254(19):9331-4.
The apoprotein of yeast cytochrome b is translated on mitochondrial ribosomes and coded for by a split gene which is located in the COB-BOX region on mitochondrial DNA. With the aid of an antibody against cytochrome b, we identified the cytochrome b-cross-reacting polypeptides of respiration-deficient mutants mapping either in coding or intervening sequences of the cytochrome b gene. Most mutations in the coding regions caused the accumulation of a single apocytochrome b fragment whose apparent molecular weight (12,000 to 26,600) depended on the map position of the mutation. In contrast, mutations in putative intervening sequences often led to multiple new polypeptides immunologically related to apocytochrome b. Some of these abnormal polypeptides were considerably larger than wild type apocytochrome b. This suggests that mutations in intervening sequences can thus generate aberrant polypeptide products.
酵母细胞色素b的脱辅基蛋白在线粒体核糖体上翻译，由位于线粒体DNA的COB - BOX区域的一个断裂基因编码。借助抗细胞色素b的抗体，我们鉴定了呼吸缺陷型突变体中与细胞色素b发生交叉反应的多肽，这些突变体定位于细胞色素b基因的编码序列或间隔序列中。编码区的大多数突变导致单个脱辅基细胞色素b片段的积累，其表观分子量（12,000至26,600）取决于突变的图谱位置。相反，假定间隔序列中的突变常常导致多个与脱辅基细胞色素b免疫相关的新多肽。其中一些异常多肽比野生型脱辅基细胞色素b大得多。这表明间隔序列中的突变可产生异常的多肽产物。
