van Mansfeld A D, van Teeffelen H A, Baas P D, Veeneman G H, van Boom J H, Jansz H S
FEBS Lett. 1984 Aug 6;173(2):351-6. doi: 10.1016/0014-5793(84)80804-2.
The bacteriophage phi X174 gene A protein cleaves the viral strand of the double-stranded replicative form (RF) DNA of the phage at a specific site, the origin. It leaves a free 3'-OH at nucleotide 4305 (G) of the phi X DNA sequence and binds covalently to the DNA. The nature and position of the covalent bond have been determined using the octadecadesoxyribonucleotide CAACTTG[32P]ATATTAATAAC. This octadecamer, which corresponds to nucleotides 4299-4316 of phi X viral DNA, is cleaved by gene A protein. Gene A protein is bound to the labelled phosphate via a tyrosyl residue, indicating that binding occurs to the nucleotide corresponding to 4306 (A) of the phi X viral DNA strand.
噬菌体φX174基因A蛋白在特定位点（即复制起点）切割噬菌体双链复制型（RF）DNA的病毒链。它在φX DNA序列的核苷酸4305（G）处留下一个游离的3'-OH，并与DNA共价结合。共价键的性质和位置已通过十八聚脱氧核糖核苷酸CAACTTG[32P]ATATTAATAAC确定。这个与φX病毒DNA的核苷酸4299 - 4316相对应的十八聚体被基因A蛋白切割。基因A蛋白通过一个酪氨酰残基与标记的磷酸基团结合，表明结合发生在与φX病毒DNA链的4306（A）相对应的核苷酸上。
