Chapter 8: Major Shifts in Prokaryotic Transcription Flashcards
Pero et al
purified proteins from infected cells, found polymerase enzymes: A, B, C
appears durng lysogenic cycle to shut down transcription except for C1 gene
dimerizes, binds DNA, & interferes with RNA polymerase transcription of cro, N, and other early genes
cooperative; facilitates RNA polymerase binding and c1 transcription??
lambda repressor / C1 (x2)
Repressor binding to OR2/1
Phage infection proess
early genes –> early gene transcripts –> early proteins (including gp28) –> middle gene transcripts (requires gp28) –> middle proteins (including gp33 and gp34) –> late gene transcripts –> late proteins
code for head, tail, and lysis proteins
late genes
lambda repressor / C1 (x2)
Repressor binding to OR2/1
appears duirng lysogenic cycle to shut down transcription except for C1 gene
dimerizes, binds DNA, & interferes with RNA polymerase transcription of cro, N, and other early genes
cooperative; facilitates RNA polymerase binding and c1 transcription??
phage DNA integrated with host (bacterial) DNA
allows lysogeny to persist indefinitely
prophage (allows?)
Viruses have (and sometimes have):
have nucleic acid enclosed in protein coat; sometimes have membranous envelope
cro & N
first genes expressed (in phage lambda) with no lambda repressors bound
B. subtilis and SPO1 phage gp28 protein (new sigma factor)
used to study specificity of RNA polymerase
gene product blocks c1 repressor gene & protein (to allow expression of other genes)
cro
delayed early gene
antiterminator: prevent RNA polymerase from stopping with gut (aka Q utilization) site and possibly host NusA
Q (x2)
Q (x2)
delayed early gene
antiterminator: prevent RNA polymerase from stopping with gut (aka Q utilization) site and possibly host NusA
binds RNA polymerase and interacts with N protein (which is bound to the nut site) creating loop and weak overall complex (i.e.?)
triggers antitermination near the nut site, strengthened/quickened by additional proteins
Nus proteins (i.e. NusA) (x2)
promoters, control c1 gene
- used to maintain lysogeny
- used to establish lysogeny by permitting leftward c1 expression prior to cro expression and directing antisense cro mRNA
PRM (1) & PRE (2)
sticky ends that can circularize
cos
delayed early genes
participate in replication
O & P (x2)
used to study specificity of RNA polymerase
B. subtilis and SPO1 phage gp28 protein (new sigma factor)