MM: bacteriophage II

what are the 2 forms of lambda genome

linear - outside the host

circular - inside the host

where does the phage lambda genome cyclize

at the cos (cohesive) ends

attP

attachment site of prophage

attB

attachment site of bacteria

function of the N protein for lytic phage lambda

PR and PL promoters full transcript wont be fully transcribed because of TR and TL

• N protein and NusABEG can bind to RNA pol to prevent termination

where is Q protein transcribed

from early genes in PR and PL

why is transcription stalled when transcribing late genes

16 bp into the mRNA, there is another promoter

• sigma 70 and RNA pol are stalled

how will protein Q help transcribe late genes

it will displace region 4 of sigma factor and allow transcription

role of O protein in lambda DNA replication

O protein congregates around the ori site

role of P protein in lambda DNA replication

hijacks host DnaB to help out for lambda replication

how does phage lambda switch from theta to rolling circle

Gam protein inhibits RecBC

• RecBC allows for theta replication

what are concatemers and when do they form during replication

• multiple copies of phage genome linked end-to-end

• form after switch to rolling circle

what determines whether lambda phage enters lytic or lysogenic cycle

CII protein

which 2 dormant promoters are activated by CII to initiate lysogeny

PI and PRM

how does CI protein maintain lysogeny

represses PR and PL

what does the Cro protein do during induction

repress PRM, CI promoter

• upregulate PR, lytic gene promoter