EARLY AND MIDDLE 11.3 Functional DNA SYNTHESIS Replication clustering in 17 essentia 7 monessen gene LATE PHASE Modification HEAD ASSEMBLY phages t7 and T4 3 nonessential gene Neck collar DNA PRECURSORS Capsid components Host DNA breakdown essential gene 2 essential nonessential gene 5 nonessential genes Figure 11. 7 The phage T4 Capsid assembly Nucleotide metabolism essential genes nonessential gene lytic cascade falls into two sential gene DNA pack Ka ging 2 nsnessengianger parts: early and quasi-late CELL STRUCTURE Membrane functions TAIL ASSEMBLY functions are concerned with 12 nonessential genes Baseplate components DNA Synthesis and gene 13 essential genes 2 nonessential genes Baseplate assemb ly expression: late functions are 5 GENE EX PRESSION 2 nonessential gene concerned with particle Translation Tube she ath 12 nonessential gene 4 essential genes assembly Transcription Tail fibers 2 essential ger essentia 5 nonessential 消当 denes nonessential geneFigure 11.7 The phage T4 lytic cascade falls into two parts: early and quasi-late functions are concerned with DNA synthesis and gene expression; late functions are concerned with particle assembly. 11.3 Functional clustering in phages T7 and T4