He L, Söderbom F, Wagner E G, Binnie U, Binns N, Masters M
Institute of Cell and Molecular Biology, University of Edinburgh, UK.
Mol Microbiol. 1993 Sep;9(6):1131-42. doi: 10.1111/j.1365-2958.1993.tb01243.x.
The replication of ColE1-related plasmids is controlled by an unstable antisense RNA, RNAI, which can interfere with the successful processing of the RNAII primer of replication. We show here that a host protein, PcnB, supports replication by promoting the decay of RNAI. In bacterial strains deleted for PcnB a stable, active form of RNAI, RNAI*, which appears to be identical to the product of 5'-end processing by RNAase E, accumulates. This leads to a reduction in plasmid copy number. We show, using a GST-PcnB fusion protein, that PcnB does not interfere with RNAI/RNAII binding in vitro. The fusion protein, like PcnB, has polyadenylating activity and is able to polyadenylate RNAI (and also another antisense RNA, CopA) in vitro.
与ColE1相关的质粒复制受不稳定的反义RNA（RNAI）控制，它会干扰复制RNAII引物的成功加工。我们在此表明，一种宿主蛋白PcnB通过促进RNAI的降解来支持复制。在缺失PcnB的细菌菌株中，一种稳定的、有活性的RNAI形式RNAI*会积累，它似乎与核糖核酸酶E进行5'端加工的产物相同。这导致质粒拷贝数减少。我们使用GST-PcnB融合蛋白表明，PcnB在体外不干扰RNAI/RNAII结合。该融合蛋白与PcnB一样具有聚腺苷酸化活性，并且能够在体外对RNAI（以及另一种反义RNA，CopA）进行聚腺苷酸化。
