Soultanas P, Dillingham M S, Wigley D B
Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
Nucleic Acids Res. 1998 May 15;26(10):2374-9. doi: 10.1093/nar/26.10.2374.
Escherichia coli ribosomal protein L3 stimulates the in vitro helicase activity of Bacillus stearothermophilus PcrA helicase upon a variety of different substrates. L3 has no intrinsic helicase or ATPase activity nor is it able to stimulate the ATPase activity of PcrA. Gel mobility shift assays revealed that the affinity of PcrA for a variety of different DNA species (single-stranded, nicked and 3'-tailed) was enhanced in the presence of L3. We suggest that the stimulatory effect of L3 upon the helicase activity of PcrA is mediated via a protein-protein interaction which promotes cooperative binding of PcrA to its DNA substrate. This activity of L3 appears to be specific for PcrA helicase.
大肠杆菌核糖体蛋白L3在多种不同底物上刺激嗜热脂肪芽孢杆菌PcrA解旋酶的体外解旋酶活性。L3没有内在的解旋酶或ATP酶活性，也不能刺激PcrA的ATP酶活性。凝胶迁移率变动分析表明，在L3存在的情况下，PcrA对多种不同DNA种类（单链、带切口和3'端带尾）的亲和力增强。我们认为，L3对PcrA解旋酶活性的刺激作用是通过蛋白质-蛋白质相互作用介导的，这种相互作用促进了PcrA与其DNA底物的协同结合。L3的这种活性似乎对PcrA解旋酶具有特异性。
