A map of phage入，showing the major genes. Regulator of入 cl,and int gene expression Regulator of cl gene Phage DNA Regulator replication of early genes 入repressor proteins cro Stabilizer cⅡ of cll protein Regulator Phage of late genes recombination PRMPRE Q proteins OL:PL OR PE Origin Lysis Excisionase of replication R proteins (for excision from Early promoters A chromosome】 xis and operators PR Late gene Integrase int Cutting of promoter Nul (for integration DNA at into chromosome cos site for A Terminase packaging -48kb Nu3 Genes for head proteins 7 and assembly 非必需区 F11 Genes for tail proteins and assembly 5 非必需区