 |
|
Title
|
|
Domain organization of the Escherichia coli RNA polymerase sigma 70 subunit.
|
|
|
Authors
|
|
E.Severinova,
K.Severinov,
D.Fenyö,
M.Marr,
E.N.Brody,
J.W.Roberts,
B.T.Chait,
S.A.Darst.
|
|
|
Ref.
|
|
J Mol Biol, 1996,
263,
637-647.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
We used limited trypsin digestion to determine the domain organization of the
Escherichia coli RNA polymerase sigma 70 subunit. Trypsin-resistant fragments
containing sigma 70 conserved region 2 (sigma 70(2)), and carboxy-terminal
fragments containing conserved regions 3 and 4 (sigma 70(3-4)) were identified
by a combination of amino acid sequencing and mass spectrometry. The domains
were studied for partial biochemical functions of sigma 70.sigma 70(2) bound
core RNA polymerase competitively with intact sigma 70. In contrast to sigma
70(2) alone, the RNA polymerase holoenzyme formed with sigma 70(2) specifically
bound a single-stranded DNA oligomer with a sequence corresponding to the
non-template strand of the -10 promoter element (the Pribnow box). Sigma 70(2)
also forms crystals that are suitable for X-ray analysis. Sigma 70(3-4) bound
the T4 AsiA protein with high affinity. The epitope for T4 AsiA on sigma 70 was
further localized to within sigma 70[551-608], comprising sigma conserved region
4.2.
|
|
|
|