ABSTRACT
The comparison of three complete aldolase B genes-including known and putative regulatory elements-is presented. The third aldolase B gene was provided by the complete aldB gene sequence (14803 bp) encoding the rabbit aldolase B isozyme. The promoter sequence alignment included the nonmammalian chicken aldolase B gene and confirms the promoter sequence conservation of those elements where trans-factor binding has been demonstrated in rat aldB. Moreover, the alignment reveals conserved sequences that may represent previously unidentified promoter elements that are present in all aldBs or specifically in the mammalian aldB promoters. One remarkable feature is a poly-purine segment found between the CAAT and TATA elements. In the mammalian promoters, this is exclusively a 9-10 bp poly-dA stretch. The avian promoter has an additional stretch of eight dG-bases immediately upstream of the poly-dA. Alignment of a portion of intron 1 of the chicken, human, and rabbit aldB genes reveals conserved sequences that are likely candidates for a reported positive activation sequence. In addition, the amino acid sequences of all eight known aldolase B isozymes is compared to the other vertebrate aldolases. A number of aldolase B-specific residues are identified that cluster in the carboxyl-portion of the sequence. With the exception of residue C268, these residues are not found near the active site, although, they are likely to be responsible for the substrate specificity of aldolase B.
Subject(s)
Carboxy-Lyases/genetics , Fructose-Bisphosphate Aldolase/genetics , Isoenzymes , Promoter Regions, Genetic , Amino Acid Sequence , Animals , Blotting, Northern , Chickens , Genomic Library , Humans , Models, Genetic , Models, Molecular , Molecular Sequence Data , Rabbits , Rats , Restriction Mapping , Sequence Analysis, DNA , Sequence Homology, Amino AcidABSTRACT
The entire AldA processed pseudogene of rabbit was isolated and characterized. The pseudogene encodes the C-terminal portion of the protein from amino acids (aa) 126-363. There are deletions, insertions and nucleotide (nt) substitutions distributed throughout the 931 bp of identity shared with the 1.4-kb mRNA. There are 21 replacement codon substitutions, including a clearly deleterious change in the stop codon. This processed pseudogene has several uncommon features: (i) it has a 5'-boundary coincident with an intron/exon junction and does not encode the entire mRNA, (ii) there is a broken direct repeat that overlaps the region of shared identity with the mRNA rather than flanking it, and (iii) there is no poly(A) sequence. This processed pseudogene probably arose by integration of a DNA copy of a partially spliced primary transcript. The structure of this gene has added implications for the timing of posttranscriptional processing events.
Subject(s)
Fructose-Bisphosphate Aldolase/genetics , Pseudogenes , Transcription, Genetic , Amino Acid Sequence , Animals , Base Sequence , DNA/genetics , DNA/isolation & purification , Molecular Sequence Data , RNA Processing, Post-Transcriptional , RNA, Messenger/genetics , Rabbits , Sequence DeletionABSTRACT
The complete nucleotide sequence of rabbit muscle aldolase mRNA has been determined from recombinant cDNA clones and from a primer-extended cDNA synthesis on the mRNA template. The sequence is composed of 1375 nucleotides, exclusive of the poly(A) tails. The 5'-untranslated region contains 62 bases including a potential ribosome-binding site. The 3'-untranslated region is 221 bases long. The remaining 1092 nucleotides are in an open reading frame coding for 364 amino acids. There is a single methionine residue preceding the NH2-terminal proline. The deduced amino acid sequence corrects a number of discrepancies between published structures as well as assignments previously missed. The sequences of the cloned cDNAs suggests there may be microheterogeneity in the messenger RNA population.
Subject(s)
Fructose-Bisphosphate Aldolase/genetics , Isoenzymes/genetics , Muscles/enzymology , RNA, Messenger/analysis , Amino Acid Sequence , Animals , Base Sequence , DNA/analysis , RabbitsABSTRACT
The recovery of several strains of Salmonella typhimurium LT-2 which had first been grown in minimal medium varies when the organisms are grown on minimal medium agar and complex medium agar. The strains tested included mutants with deficiencies in DNA-repair systems (uvrB-and rec-), a deep rough (rfa-) mutant, and a double mutant carrying both the uvrB- and the rfa-mutation. The uvrB- and rec-mutations imparted sensitivity to complex medium agar. The rfa-mutation suppressed the sensitivity of the uvrB-mutant to complex medium agar. Differences in colony-forming ability were not observed when the bacteria were first grown in the complex medium broth.
