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 gene
Figure 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
bound by 11.3 Functional Cll alone clustering in bound by cll polymerase phages T7 and T4 八 -50-40-3020-10+10 Figure 11 24 RNA Startpoint polymerase binds Usual toI re only in the sequence sequence at -35 at-10 presence of CIl TTGACA TATAAT which contacts the GCAACGCAAA CAAACGTGCTTGGIATACATTCATAAAGGAATCTA CGTTGCGTTTGTTTGCACGAACCATAT GTAAGTATTTCCTTAGAT region around -35 cyR mutations cvl mutations 消当 polymerase binding polymerase binding affect cll binding
Figure 11.24 RNA polymerase binds to PRE only in the presence of CII, which contacts the region around -35. 11.3 Functional clustering in phages T7 and T4
LYTIC CASCADE LYSOGENIC 11. 4 The lambda ESTAB凵 SHMENT lytic cascade relies ■■国■■■■■■ repression mmediate early on antitermination pression o= negative regulator■L antiterminator Figure 11.8 The Delayed early ctivation regulators中m中 -p cl repress recom bination genes lambda lytic repli cation genes Q=antiterminator cascade Is interlocked with Late 10 head gene OGENIC the circuitry for 11 tail genes/ MAINTENANCE 2 lysis gene lysogeny. 消当 PROGENY PHAGE
Figure 11.8 The lambda lytic cascade is interlocked with the circuitry for lysogeny. 11.4 The lambda lytic cascade relies on antitermination
11.4 The lambda lytic cascade relies on antitermination Promoters for the lytic cycle PLPR PR Head genes Tail genes Recombination Regulation Replicatiobysis AWBC№3DEF1 FZvGTHLKNJatt ir? xisoBycl/f N c crO c/O PQ S月 Required for: by sogeny ci maint ains cf lysogeny and lysis N turns on delayed early lysogeny c/is ly sogenic repressor SIS cro turns off repressor lysogeny cl turns on repressor SIS Q turns on late Figure 11. 9 The lambda map shows clustering of related i*k functions. The genome is 48, 514 bp
Figure 11.9 The lambda map shows clustering of related functions. The genome is 48,514 bp. 11.4 The lambda lytic cascade relies on antitermination