scholarly journals Mutations affecting two adjacent amino acid residues in the alpha subunit of RNA polymerase block transcriptional activation by the bacteriophage P2 Ogr protein.

1994 ◽  
Vol 176 (24) ◽  
pp. 7430-7438 ◽  
Author(s):  
D J Ayers ◽  
M G Sunshine ◽  
E W Six ◽  
G E Christie
Keyword(s):  
Amino Acid ◽  
Rna Polymerase ◽  
Transcriptional Activation ◽  
Alpha Subunit ◽  
Amino Acid Residues ◽  
Bacteriophage P2 ◽  
Adjacent Amino Acid

scholarly journals The Escherichia coli RNA polymerase alpha subunit and transcriptional activation by bacteriophage lambda CII protein.

1998 ◽  
Vol 45 (1) ◽  
pp. 271-280 ◽  
Author(s):  
M Gabig ◽  
M Obuchowski ◽  
A Ciesielska ◽  
B Latała ◽  
A Wegrzyn ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Transcriptional Activation ◽  
Bacteriophage Lambda ◽  
Alpha Subunit ◽  
Single Amino Acid ◽  
Amino Acid Residues ◽  
A Subunit ◽  
Rpoa Gene

Bacteriophage lambda is not able to lysogenise the Escherichia coli rpoA341 mutant. This mutation causes a single amino acid substitution Lys271Glu in the C-terminal domain of the RNA polymerase alpha subunit (alphaCTD). Our previous studies indicated that the impaired lysogenisation of the rpoA341 host is due to a defect in transcriptional activation by the phage CII protein and suggested a role for alphaCTD in this process. Here we used a series of truncation and point mutants in the rpoA gene placed on a plasmid to investigate the process of transcriptional activation by the cII gene product. Our results indicate that amino-acid residues 265, 268 and 271 in the a subunit may play an important role in the CII-mediated activation of the pE promoter (most probably residue 271) or may be involved in putative interactions between alphaCTD and an UP-like element near pE (most probably residues 265 and 268). Measurement of the activity of pE-lacZ, pI-lacZ and p(aQ)-lacZ fusions in the rpoA+ and rpoA341 hosts demonstrated that the mechanism of activation of these CII-dependent promoters may be in each case different.

scholarly journals RPC53 encodes a subunit of Saccharomyces cerevisiae RNA polymerase C (III) whose inactivation leads to a predominantly G1 arrest.

1992 ◽  
Vol 12 (10) ◽  
pp. 4314-4326 ◽  
Author(s):  
C Mann ◽  
J Y Micouin ◽  
N Chiannilkulchai ◽  
I Treich ◽  
J M Buhler ◽  
...  
Keyword(s):  
Cell Division ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Essential Gene ◽  
Temperature Sensitive ◽  
G1 Arrest ◽  
Restrictive Temperature ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Carboxy Terminal

RPC53 is shown to be an essential gene encoding the C53 subunit specifically associated with yeast RNA polymerase C (III). Temperature-sensitive rpc53 mutants were generated and showed a rapid inhibition of tRNA synthesis after transfer to the restrictive temperature. Unexpectedly, the rpc53 mutants preferentially arrested their cell division in the G1 phase as large, round, unbudded cells. The RPC53 DNA sequence is predicted to code for a hydrophilic M(r)-46,916 protein enriched in charged amino acid residues. The carboxy-terminal 136 amino acids of C53 are significantly similar (25% identical amino acid residues) to the same region of the human BN51 protein. The BN51 cDNA was originally isolated by its ability to complement a temperature-sensitive hamster cell mutant that undergoes a G1 cell division arrest, as is true for the rpc53 mutants.

scholarly journals The C-Terminal Hydrophobic Domain of Hepatitis C Virus RNA Polymerase NS5B Can Be Replaced with a Heterologous Domain of Poliovirus Protein 3A

2006 ◽  
Vol 80 (22) ◽  
pp. 11343-11354 ◽  
Author(s):  
Haekyung Lee ◽  
Ying Liu ◽  
Edison Mejia ◽  
Aniko V. Paul ◽  
Eckard Wimmer
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Decisive Role ◽  
Amino Acid Residues ◽  
Subgenomic Replicon ◽  
Hydrophobic Domain ◽  
Virus Rna ◽  
Membrane Bound

ABSTRACT Replication of the plus-stranded RNA genome of hepatitis C virus (HCV) occurs in a membrane-bound replication complex consisting of viral and cellular proteins and viral RNA. NS5B, the RNA polymerase of HCV, is anchored to the membranes via a C-terminal 20-amino-acid-long hydrophobic domain, which is flanked on each side by a highly conserved positively charged arginine. Using a genotype 1b subgenomic replicon (V. Lohmann, F. Korner, J. O. Koch, U. Herian, L. Theilmann, and R. Bartensclager, Science 285:110-113, 1999), we determined the effect of mutations of some highly conserved residues in this domain. The replacement of arginine 570 with alanine completely abolished the colony-forming ability by the replicon, while a R591A change was found to be highly detrimental to replication, viability, and membrane binding by the mutant NS5B protein. Mutations of two other highly conserved amino acids (L588A and P589A) reduced but did not eliminate colony formation. It was of interest, if specific amino acid residues play a role in membrane anchoring of NS5B and replication, to determine whether a complete exchange of the NS5B hydrophobic domain with a domain totally unrelated to NS5B would ablate replication. We selected the 22-amino-acid-long hydrophobic domain of poliovirus polypeptide 3A that is known to adopt a transmembrane configuration, thereby anchoring 3A to membranes. Surprisingly, either partial or full replacement of the NS5B hydrophobic domain with the anchor sequences of poliovirus polypeptide 3A resulted in the replication of replicons whose colony-forming abilities were reduced compared to that of the wild-type replicon. Upon continued passage of the replicon in Huh-7 cells in the presence of neomycin, the replication efficiency of the replicon increased. However, the sequence of the poliovirus polypeptide 3A hydrophobic domain, in the context of the subgenomic HCV replicon, was stably maintained throughout 40 passages. Our results suggest that anchoring NS5B to membranes is necessary but that the amino acid sequence of the anchor per se does not require HCV origin. This suggests that specific interactions between the NS5B hydrophobic domain and other membrane-bound factors may not play a decisive role in HCV replication.

A novel gene, MEL1, mapped to 1p36.3 is highly homologous to the MDS1/EVI1 gene and is transcriptionally activated in t(1;3)(p36;q21)-positive leukemia cells

Blood ◽  
2000 ◽  
Vol 96 (9) ◽  
pp. 3209-3214 ◽  
Author(s):  
Naomi Mochizuki ◽  
Seiichi Shimizu ◽  
Toshiro Nagasawa ◽  
Hideo Tanaka ◽  
Masafumi Taniwaki ◽  
...  
Keyword(s):  
Amino Acid ◽  
Transcriptional Activation ◽  
Zinc Finger Protein ◽  
Fetal Liver ◽  
Amino Acid Sequences ◽  
Leukemia Cells ◽  
The Novel ◽  
Amino Acid Residues ◽  
Novel Gene ◽  
Pr Domain

The reciprocal translocation t(1;3)(p36;q21) occurs in a subset of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), which is frequently characterized by trilineage dysplasia, in particular dysmegakaryocytopoiesis, and poor prognosis. Previously, the breakpoint cluster region (BCR) at 3q21 was identified within a 60-kilobase (kb) region centromeric to the BCR of 3q21q26 syndrome and that at 1p36.3 within a 90-kb region. In this study, genes were searched near the breakpoints at 1p36.3, and a novel gene was isolated that encoded a zinc finger protein with a PR domain, which is highly homologous to theMDS1/EVI1 gene. The novel gene, designated asMEL1(MDS1/EVI1-like gene 1), with 1257 amino acid residues is 64% similar in nucleotide and 63% similar in amino acid sequences to MDS1/EVI1 with the same domain structure. The MEL1 gene is expressed in leukemia cells with t(1;3) but not in other cell lines or bone marrow, spleen, and fetal liver, suggesting that MEL1 is specifically in the t(1;3)(p36;q21)-positive MDS/AML. On the basis of the positional relationship between the EVI1 and MEL1 genes in each translocation, it was suggested that both genes are transcriptionally activated by the translocation of the 3q21 region with the Ribophorin I gene. Because of the transcriptional activation of the EVI1 family genes in both t(1;3)(p36;q21)-positive MDS/AML and 3q21q26 syndrome, it is suggested that they share a common molecular mechanism for the leukemogenic transformation of the cells.

RPC53 encodes a subunit of Saccharomyces cerevisiae RNA polymerase C (III) whose inactivation leads to a predominantly G1 arrest

1992 ◽  
Vol 12 (10) ◽  
pp. 4314-4326
Author(s):  
C Mann ◽  
J Y Micouin ◽  
N Chiannilkulchai ◽  
I Treich ◽  
J M Buhler ◽  
...  
Keyword(s):  
Cell Division ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Essential Gene ◽  
Temperature Sensitive ◽  
G1 Arrest ◽  
Restrictive Temperature ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Carboxy Terminal

RPC53 is shown to be an essential gene encoding the C53 subunit specifically associated with yeast RNA polymerase C (III). Temperature-sensitive rpc53 mutants were generated and showed a rapid inhibition of tRNA synthesis after transfer to the restrictive temperature. Unexpectedly, the rpc53 mutants preferentially arrested their cell division in the G1 phase as large, round, unbudded cells. The RPC53 DNA sequence is predicted to code for a hydrophilic M(r)-46,916 protein enriched in charged amino acid residues. The carboxy-terminal 136 amino acids of C53 are significantly similar (25% identical amino acid residues) to the same region of the human BN51 protein. The BN51 cDNA was originally isolated by its ability to complement a temperature-sensitive hamster cell mutant that undergoes a G1 cell division arrest, as is true for the rpc53 mutants.

scholarly journals Lineage-Specific Amino Acid Substitutions in Region 2 of the RNA Polymerase σ Subunit Affect the Temperature of Promoter Opening

2008 ◽  
Vol 190 (8) ◽  
pp. 3088-3092 ◽  
Author(s):  
N. Barinova ◽  
E. Zhilina ◽  
I. Bass ◽  
V. Nikiforov ◽  
A. Kulbachinskiy
Keyword(s):  
Amino Acid ◽  
Rna Polymerase ◽  
Amino Acid Substitutions ◽  
Amino Acid Residues ◽  
Specific Amino Acid ◽  
Promoter Recognition

ABSTRACT Highly conserved amino acid residues in region 2 of the RNA polymerase σ subunit are known to participate in promoter recognition and opening. We demonstrated that nonconserved residues in this region collectively determine lineage-specific differences in the temperature of promoter opening.

scholarly journals Cloning and structural characterization of the genes coding for adenosylcobalamin-dependent methylmalonyl-CoA mutase from Propionibacterium shermanii

1989 ◽  
Vol 260 (2) ◽  
pp. 345-352 ◽  
Author(s):  
E N Marsh ◽  
N McKie ◽  
N K Davis ◽  
P F Leadlay
Keyword(s):  
Amino Acid ◽  
Alpha Subunit ◽  
Nucleotide Sequence Analysis ◽  
Homologous Region ◽  
Amino Acid Residues ◽  
Upstream Gene ◽  
Ancestral Gene ◽  
Propionibacterium Shermanii ◽  
Hybridization Probes

The structural genes coding for both subunits of adenosylcobalamin-dependent methylmalonyl-CoA mutase from the Gram-positive bacterium Propionibacterium shermanii have been cloned, with the use of synthetic oligonucleotides as primary hybridization probes. The genes are closely linked and are transcribed in the same direction. Nucleotide sequence analysis of 4.5 kb of DNA encompassing both genes allowed us to infer the complete amino acid sequence of the two subunits: the beta-subunit is the product of the upstream gene, and consists of 638 amino acid residues (Mr 69465) and the alpha-subunit consists of 728 amino acid residues (Mr 80,147). There is a very close structural homology between the two subunits, reflecting the probable duplication of a common ancestral gene. A sequence present only in the alpha-subunit is significantly homologous to a portion of the sequence of the methylmalonyl-CoA-binding subunit of transcarboxylase from P. shermanii [Samols, Thornton, Murtif, Kumar, Haase & Wood (1988) J. Biol. Chem. 263, 6461-6464], and this homologous region may form part of the CoA ester-binding site in both enzymes.

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