The Conserved Motif in Hydrophilic Loop 2/3 and Loop 8/9 of the Lactose Permease of Escherichia coli. Analysis of Suppressor Mutations

2000 ◽  
Vol 176 (2) ◽  
pp. 159-168 ◽  
Author(s):  
S.M. Cain ◽  
E.A. Matzke ◽  
R.J. Brooker
Keyword(s):  
Escherichia Coli ◽  
Lactose Permease ◽  
Conserved Motif ◽  
Suppressor Mutations ◽  
Hydrophilic Loop ◽  
Loop 2

scholarly journals The Conserved Motif, GXXX(D/E)(R/K)XG[X](R/K)(R/K), in Hydrophilic Loop 2/3 of the Lactose Permease

1995 ◽  
Vol 270 (27) ◽  
pp. 16251-16257 ◽  
Author(s):  
Amy E. Jessen-Marshall ◽  
Nanette J. Paul ◽  
Robert J. Brooker
Keyword(s):  
Lactose Permease ◽  
Conserved Motif ◽  
Hydrophilic Loop ◽  
Loop 2

Roles of Charged Residues in the Conserved Motif, G-X-X-X-D/E-R/K-X-G-[X]-R/K-R/K, of the Lactose Permease of Escherichia coli

2000 ◽  
Vol 174 (1) ◽  
pp. 31-40 ◽  
Author(s):  
N.J. Pazdernik ◽  
E.A. Matzke ◽  
A.E. Jessen-Marshall ◽  
R.J. Brooker
Keyword(s):  
Escherichia Coli ◽  
Lactose Permease ◽  
Conserved Motif ◽  
Charged Residues

scholarly journals Differential Suppression of priA2::kan Phenotypes in Escherichia coli K-12 by Mutations in priA, lexA, and dnaC

Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Steven J Sandler ◽  
Hardeep S Samra ◽  
Alvin J Clark
Keyword(s):  
Escherichia Coli ◽  
Dna Replication ◽  
Mutant Allele ◽  
Wild Type ◽  
Suppressor Mutations ◽  
Dnab Helicase ◽  
K 12 ◽  
Extragenic Suppressors ◽  
Assembly Activity

Abstract First identified as an essential component of the ϕX174 in vitro DNA replication system, PriA has ATPase, helicase, translocase, and primosome-assembly activities. priA1::kan strains of Escherichia coli are sensitive to UV irradiation, deficient in homologous recombination following transduction, and filamentous. priA2::kan strains have eightfold higher levels of uninduced SOS expression than wild type. We show that (1) priA1::kan strains have eightfold higher levels of uninduced SOS expression, (2) priA2::kan strains are UVS and Rec−, (3) lexA3 suppresses the high basal levels of SOS expression of a priA2::kan strain, and (4) plasmid-encoded priA300 (K230R), a mutant allele retaining only the primosome-assembly activity of priA+, restores both UVR and Rec+ phenotypes to a priA2::kan strain. Finally, we have isolated 17 independent UVR Rec+ revertants of priA2::kan strains that carry extragenic suppressors. All 17 map in the C-terminal half of the dnaC gene. DnaC loads the DnaB helicase onto DNA as a prelude for primosome assembly and DNA replication. We conclude that priA's primosome-assembly activity is essential for DNA repair and recombination and that the dnaC suppressor mutations allow these processes to occur in the absence of priA.

scholarly journals Functional roles of Glu-269 and Glu-325 within the lactose permease of Escherichia coli.

1994 ◽  
Vol 269 (10) ◽  
pp. 7379-7386 ◽  
Author(s):  
P.J. Franco ◽  
R.J. Brooker
Keyword(s):  
Escherichia Coli ◽  
Lactose Permease ◽  
Functional Roles

Design of a membrane protein for site-specific proteolysis: properties of engineered factor Xa protease sites in the lactose permease of Escherichia coli

Biochemistry ◽  
1995 ◽  
Vol 34 (4) ◽  
pp. 1107-1112 ◽  
Author(s):  
Miklos Sahin-Toth ◽  
Rhonda L. Dunten ◽  
H. Ronald Kaback
Keyword(s):  
Escherichia Coli ◽  
Membrane Protein ◽  
Factor Xa ◽  
Lactose Permease ◽  
Site Specific

scholarly journals Topography of lactose permease from Escherichia coli.

1988 ◽  
Vol 263 (31) ◽  
pp. 15906-15914 ◽  
Author(s):  
M G Page ◽  
J P Rosenbusch
Keyword(s):  
Escherichia Coli ◽  
Lactose Permease

Photoreversal of UV-potentiated glutamine tRNA suppressor mutations in excision proficient Escherichia coli

1997 ◽  
Vol 383 (3) ◽  
pp. 231-242 ◽  
Author(s):  
R Bockrath ◽  
B.-H Li
Keyword(s):  
Escherichia Coli ◽  
Suppressor Mutations

Genetic exploration of interactive domains in RNA polymerase II subunits

1990 ◽  
Vol 10 (5) ◽  
pp. 1908-1914
Author(s):  
C Martin ◽  
S Okamura ◽  
R Young
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Temperature Sensitive ◽  
Suppressor Mutations ◽  
Region I ◽  
Temperature Sensitive Mutation ◽  
Allele Specific ◽  
Separate Protein

The two large subunits of RNA polymerase II, RPB1 and RPB2, contain regions of extensive homology to the two large subunits of Escherichia coli RNA polymerase. These homologous regions may represent separate protein domains with unique functions. We investigated whether suppressor genetics could provide evidence for interactions between specific segments of RPB1 and RPB2 in Saccharomyces cerevisiae. A plasmid shuffle method was used to screen thoroughly for mutations in RPB2 that suppress a temperature-sensitive mutation, rpb1-1, which is located in region H of RPB1. All six RPB2 mutations that suppress rpb1-1 were clustered in region I of RPB2. The location of these mutations and the observation that they were allele specific for suppression of rpb1-1 suggests an interaction between region H of RPB1 and region I of RPB2. A similar experiment was done to isolate and map mutations in RPB1 that suppress a temperature-sensitive mutation, rpb2-2, which occurs in region I of RPB2. These suppressor mutations were not clustered in a particular region. Thus, fine structure suppressor genetics can provide evidence for interactions between specific segments of two proteins, but the results of this type of analysis can depend on the conditional mutation to be suppressed.

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