Casjens S, Eppler K, Sampson L, Parr R, Wyckoff E
Department of Cellular, Viral and Molecular Biology, University of Utah Medical Center, Salt Lake City 84132.
Genetics. 1991 Apr;127(4):637-47. doi: 10.1093/genetics/127.4.637.
The mechanism by which dsDNA is packaged by viruses is not yet understood in any system. Bacteriophage P22 has been a productive system in which to study the molecular genetics of virus particle assembly and DNA packaging. Only five phage encoded proteins, the products of genes 3, 2, 1, 8 and 5, are required for packaging the virus chromosome inside the coat protein shell. We report here the construction of a detailed genetic and physical map of these genes, the neighboring gene 4 and a portion of gene 10, in which 289 conditional lethal amber, opal, temperature sensitive and cold sensitive mutations are mapped into 44 small (several hundred base pair) intervals of known sequence. Knowledge of missense mutant phenotypes and information on the location of these mutations allows us to begin the assignment of partial protein functions to portions of these genes. The map and mapping strains will be of use in the further genetic dissection of the P22 DNA packaging and prohead assembly processes.
病毒包装双链DNA（dsDNA）的机制在任何系统中都尚未完全明晰。噬菌体P22一直是研究病毒颗粒组装和DNA包装分子遗传学的有效系统。仅需五种噬菌体编码蛋白（基因3、2、1、8和5的产物）就能将病毒染色体包装到衣壳蛋白壳内。我们在此报告这些基因、相邻的基因4以及基因10的一部分的详细遗传和物理图谱构建情况，其中289个条件致死性琥珀突变、乳白突变、温度敏感突变和冷敏感突变被定位到44个已知序列的小（几百个碱基对）区间。错义突变体表型的知识以及这些突变位置的信息使我们能够开始将部分蛋白质功能分配到这些基因的部分区域。该图谱和定位菌株将用于进一步对P22 DNA包装和前头部组装过程进行遗传剖析。
