Promoter%20recognition%20by%20sigma%20factors

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Promoter recognition by sigma factors
Sigma factor
RNA polymerase core enzyme
Figure from Griffiths et al (1996) Introduction
to Genetic Analysis, 6th ed., WH Freeman and Co.
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Promoter recognition by sigma factors
Figure from Griffiths et al (1996) Introduction
to Genetic Analysis, 6th ed., WH Freeman and Co.
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Promoter recognition by sigma factors
Figure from Griffiths et al (1996) Introduction
to Genetic Analysis, 6th ed., WH Freeman and Co.
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Promoter recognition by sigma factors
uvrB Repair DNA damage TTGTTGGCATAATTAAGTACGACGAG
TAAAATTAC ATACCT recA DNArecombination CACTTGAT
ACTGTA.TGAGCATACAGTATAATTGC TTCAACA rrnAB Ribosom
alRNA CTCTTGTCAGGCCG.GAATAACTCCCTATAATGCGCCACCACTG
str Ribosomal protein TTCTTGACACCTT.TCGGCATCGCCCT
AAAATTCG GCGTCG rpoA RNA polymerase TTCTTGCAAAGT
TGGGTTGAGCTGGCTAGATTAGC CAGCCA
TTGaca
TAtAaT R
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Promoter recognition by sigma factors
TTGaca
TAtAaT R
uvrB Repair DNA damage TTGTTGGCATAATTAAGTACGACGAG
TAAAATTAC ATACCT recA DNArecombination CACTTGAT
ACTGTA.TGAGCATACAGTATAATTGC TTCAACA rrnAB Ribosom
alRNA CTCTTGTCAGGCCG.GAATAACTCCCTATAATGCGCCACCACTG
str Ribosomal protein TTCTTGACACCTT.TCGGCATCGCCCT
AAAATTCG GCGTCG rpoA RNA polymerase TTCTTGCAAAGT
TGGGTTGAGCTGGCTAGATTAGC CAGCCA
Kp nifE nitrogenase accessory CTTCTGGAGCGCGAATTGCA
TCTTCCCCCT Kp nifU nitrogenase accessory
TCTCTGGTATCGCAATTGCT AGTTCGTTAT Kp
nifB nitrogenase accessory CCTCTGGTACAGCATTTGCA
GCAGGAAGGT Kp nifH nitrogenase CGGCTGGTATGTTCCCTGC
ACTTCTCTGCTG Kp nifM nitrogenase accessory
TGGCTGGCCGGAAATTTGCA ATACAGGGAT Kp
nifF nitrogenase accessory AACCTGGCACAGCCTTCGCA
ATACCCCTGC Kp nifL nitrogenase regulatn ATAAGGGCG
CACGGTTTGCATGGTTATCACC glnA P2 glutamine
synthetase AAGTTGGCACAGATTTCGCTTTATCTTTTTT
CTGG-A
TTGCA
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Sigma factors in sporulation
Starvation (and other signals)Stage 0
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Sigma factors in sporulation
H
H
Starvation (and other signals)Stage II/III
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Sigma factors in sporulation
Starvation (and other signals)Stage 0
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Sigma factors in sporulation
H
H
Starvation (and other signals)Stage II/III
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Sigma factors in sporulation
Starvation (and other signals)Stage III
Starvation (and other signals)Stage IV
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Sigma factors in sporulation
Sporulation regulated sigma factor cascade
but what regulates the sigma factors?

• Not transcriptional control
• What kind of post-transcriptional control?
• How are events coordinated? Checkpoints?

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Sigma factors in sporulation
Old gene names New gene names Protein names
Location
rpoD sigA ?37,?A vegetative
spo0H sigH ?H vegetative
spoIIG sigE ?37,?E mother cell
spoIIA sigF ?F forespore
spoIIIC sigK ?K mother cell
spoIIIG sigG ?G forespore