Functional organization of the retrotransposon Ty from Saccharomyces cerevisiae: Ty protease is required for transposition.
Functional organization of the retrotransposon Ty from Saccharomyces cerevisiae: Ty protease is required for transposition.
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酿酒酵母反转录转座子 Ty 的功能组织：转座需要 Ty 蛋白酶。
DOI：
10.1128/mcb.8.4.1421-1431.1988
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发表时间：
1988
影响因子：
5.3
通讯作者：
Garfinkel,DJ
中科院分区：
文献类型：
--
作者：
Youngren,SD;Boeke,JD;Sanders,NJ;Garfinkel,DJ
我们利用体外产生的几个突变进一步表征了酿酒酵母（saccharomyces cerevisiae）转座活性反转录转座子TyH3的TyB基因编码产物的功能。与逆转录病毒蛋白酶同源的tyb核心蛋白结构域附近的突变对Ty蛋白加工、Ty病毒样颗粒的生理和转位有显著影响。tya蛋白和tyb蛋白的加工都需要Ty蛋白酶。蛋白酶的突变导致了形态和功能异常的Ty病毒样颗粒的合成。突变颗粒在体外表现出逆转录酶活性，但不能合成Ty DNA。突变颗粒中存在Ty RNA，但含量很低。当蛋白酶结构域发生突变时，基因标记元件的转座停止，这表明Ty蛋白酶对转座至关重要。其中一个突变还定义了一个编码活性逆转录酶的tybenc片段。这些结果表明，Ty蛋白酶，像它的逆转录病毒对应物一样，在这些元件的颗粒组装、复制和转位中起着重要作用。
We used several mutations generated in vitro to further characterize the functions of the products encoded by the TyB gene of the transpositionally active retrotransposon TyH3 fromSaccharomyces cerevisiae. Mutations close to a core protein domain ofTyB, which is homologous to retroviral proteases, have striking effects on Ty protein processing, the physiology of Ty viruslike particles, and transposition. The Ty protease is required for processing of bothTyAandTyBproteins. Mutations in the protease resulted in the synthesis of morphologically and functionally aberrant Ty viruslike particles. The mutant particles displayed reverse transcriptase activity, but did not synthesize Ty DNA in vitro. Ty RNA was present in the mutant particles, but at very low levels. Transposition of a genetically tagged element ceased when the protease domain was mutated, demonstrating that Ty protease is essential for transposition. One of these mutations also defined a segment ofTyBencoding an active reverse transcriptase. These results indicate that the Ty protease, like its retroviral counterpart, plays an important role in particle assembly, replication, and transposition of these elements.