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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Extracts from Escherichia coli, wild type and chlB, chlC, chlD, chlE, and chlG, but not chlA mutants, were able to reconstitute the nitrate reductase activity in Nicotiana tabacum cnx68 and Hyoscyamus muticus MA-2 mutant extracts. Because cnx68 and MA-2 lack the molybdenum cofactor required for nitrate reductase activity, these results indicate that the functional chlA gene is essential to produce the molybdenum cofactor in E. coli. A clone containing a gene capable of complementing the chlA mutation SA493 was obtained on a large cosmid pJT1.
A 1
.9 kb BclI fragment subcloned from pJT1 in the vector plasmid pBR322 was shown to complement the chlA SA493 mutant when inserted in either of the two possible orientations. This suggested that the chlA gene was contained intact, including its own promoter, on the 1.9 kb BclI fragment.
J
Mol
Appl Genet 1983
PMID:Reconstitution of plant nitrate reductase by Escherichia coli extracts and the molecular cloning of the chlA gene of Escherichia coli K12. 636 88
Four fragments from the maxicircle DNA of Leishmania tarentolae cloned into the selectable Saccharomyces cerevisiae shuttle vector, YIp5, exhibited autonomous replicating sequence (ars) activity. Two of the fragments (pSK120, pSK152) produced large yeast transformant colonies and two (pSK30, pSK150) produced small colonies. All yeast transformants contained extrachromosomal self replicating YIp5 hybrid plasmids as shown by mitotic instability in non selective medium and by the transformation of Escherichia coli with yeast minilysates and recovery of the plasmid from the transformed bacteria. The copy numbers of pSK30, pSK150 and pSK152 in the transformed yeast were approximately the same as that of the YRp12 control, which contains the yeast arsl element; the copy number of pSK120, however, was at least 10 fold lower.
A 1
.87 kb subfragment of the pSK120 fragment also showed strong ars activity. The entire DNA sequences of the pSK120, pSK152 and pSK150 fragments are known, and several yeast 11 mer consensus ars sequences are present within each fragment. In addition there is a sequence (Lt ars 189) within the pSK152 subclone that has 78% similarity with a 189 nt sequence of an ars element from the Crithidia fasciculata maxicircle (Cf ars 189), implying an evolutionary conservation of this putative origin of replication in at least two different kinetoplastid species. The relative positions of the Lt ars 189 sequence in the L. tarentolae maxicircle map and the Cf ars 189 sequence in the C. fasciculata map with respect to the 9 and 12 S ribosomal genes are similar, implying an overall conservation of gene order in this portion of the transcribed regions of these two species and perhaps in all kinetoplastid species.
Mol
Biochem Parasitol 1984 Nov
PMID:Autonomous replication sequences in the maxicircle kinetoplast DNA of Leishmania tarentolae. 639 15
A 1
.7-kbp DNA region from the 10.2-kb cluster containing the five rainbow trout histone genes has been subcloned in pBR322 and completely sequenced. It contains a trout histone H1 gene together with its 5' and 3' flanking sequences. This H1 gene codes for a H1 variant different from the major trout testis H1 previously sequenced by Macleod et al. (1977). Northern blots of total RNA from trout testis, kidney, and liver indicate that this H1 gene is expressed in all three tissues but that the level of H1 mRNA is much higher in testis than in other tissues. The lack of heterogeneity in the sizes and 5' initiation sites of trout H1 mRNAs is surprising in view of the substantial heterogeneity of H1 variant proteins observed previously. The coding sequence of the H1 gene shows strong evidence of repeated partial duplications of a hexapeptide motif of the form Ala.Ala.Ala.Lys.Lys.Pro and of a pentapeptide phosphorylation-site sequence, Lys.Ser.Pro.Lys.Lys, during its evolution. Comparisons are drawn between this gene and the coding sequences of other vertebrate H1 genes from chicken and Xenopus, and a strong homology is seen in the region of amino acids 22-101, which form the hydrophobic "head" of the H1 molecule. The 5' and 3' regulatory signals in the trout H1 are also compared with those of H1 genes from other sequences.
J
Mol
Evol
PMID:An H1 histone gene from rainbow trout (Salmo gairdnerii). 644 28
Trichorzianine
A 1
is one of the main components of a mixture of related antibiotic peptides (trichorzianines) produced by the fungus Trichoderma harzianum. Good crystals were obtained and allowed X-ray diffraction up to 0.8 A resolution. The space group is orthorhombic, C222(1), Z = 8, a = 64.8 (1) A, b = 9.33 (3) A, c = 39.9 (1) A. The solvent content is only 12%, preventing a heavy ion diffusion. So, we are trying to obtain the structure by direct methods.
J
Mol
Biol 1983 Nov 05
PMID:Crystallization and preliminary X-ray diffraction results of trichorzianine A 1, a peptide with nineteen residues from Trichoderma harzianum. 663 70
The tryptophan synthase alpha subunit catalyzes the conversion of indole-3-glycerolphosphate to indole, the penultimate reaction in the biosynthesis of the essential amino acid tryptophan. A cDNA encoding Arabidopsis thaliana tryptophan synthase alpha(TSA1) was isolated by complementation of an Escherichia coli delta trpA mutation and by polymerase chain reaction amplification from a cDNA library using degenerate primers. A TSA1 genomic clone was also isolated and 5 kb of the DNA sequence determined. A single sequence in the Arabidopsis genome with homology to the TSA1 cDNA was detected by high-stringency genomic Southern blot hybridization. In contrast under hybridization conditions of reduced stringency, one or two additional homologous sequences were observed.
A 1
.4 kb transcript was detected in wild-type RNA with the TSA1 cDNA as a probe. Several lines of evidence, including immunoaffinity chromatography, suggest that the active A. thaliana tryptophan synthase enzyme consists of a heterosubunit complex, presumably analogous to the prokaryotic alpha 2 beta 2 complex. Immunoblot analysis indicated that the plant alpha and beta subunits are present throughout development.
Mol
Gen Genet 1995 Oct 25
PMID:Arabidopsis thaliana tryptophan synthase alpha: gene cloning, expression, and subunit interaction. 747 68
We present phylogenetic evidence that a group I intron in an angiosperm mitochondrial gene arose recently by horizontal transfer from a fungal donor species.
A 1
,716-bp fragment of the mitochondrial coxI gene from the angiosperm Peperomia polybotrya was amplified via the polymerase chain reaction and sequenced. Comparison to other coxI genes revealed a 966-bp group I intron, which, based on homology with the related yeast coxI intron aI4, potentially encodes a 279-amino-acid site-specific DNA endonuclease. This intron, which is believed to function as a ribozyme during its own splicing, is not present in any of 19 coxI genes examined from other diverse vascular plant species. Phylogenetic analysis of intron origin was carried out using three different tree-generating algorithms, and on a variety of nucleotide and amino acid data sets from the intron and its flanking exon sequences. These analyses show that the Peperomia coxI gene intron and exon sequences are of fundamentally different evolutionary origin. The Peperomia intron is more closely related to several fungal mitochondrial introns, two of which are located at identical positions in coxI, than to identically located coxI introns from the land plant Marchantia and the green alga Prototheca. Conversely, the exon sequence of this gene is, as expected, most closely related to other angiosperm coxI genes. These results, together with evidence suggestive of co-conversion of exonic markers immediately flanking the intron insertion site, lead us to conclude that the Peperomia coxI intron probably arose by horizontal transfer from a fungal donor, using the double-strand-break repair pathway. The donor species may have been one of the symbiotic mycorrhizal fungi that live in close obligate association with most plants.
J
Mol
Evol 1995 Nov
PMID:Fungal origin by horizontal transfer of a plant mitochondrial group I intron in the chimeric CoxI gene of Peperomia. 749 Jul 70
Transcription of the group A streptococcal M12 protein gene (emm12) and the C5a peptidase gene (scpA), which encodes an inhibitor of complement-mediated chemotaxis, was previously shown to depend on a third genetic locus, designated virR.
A 1
.6 kb region of DNA which is 200 bp upstream of emm12 and is thought to contain the virR locus, was sequenced. An open reading frame which overlaps deletion mutations that define virR was identified. The sequence of the encoded VirR protein, which was deduced to contain 499 amino acids, is characteristic of cytoplasmic proteins. Comparison of the VirR protein to a variety of DNA binding proteins, such as lambda Cro, revealed a DNA binding motif. VirR was also compared to the M6 positive regulator, mry, and found to be 98% homologous. The predicted virR promoter is preceded by two sets of inverted repeats, in contrast to mry which is preceded by one repeat. Introduction of virR on the shuttle vector pAM401 into a strain of group A Streptococcus with a deletion in the chromosomal virR gene demonstrated that the VirR protein activated transcription of both emm12 and scpA genes in trans. Analysis of RNA by Northern blot using virR-specific probes identified two virR transcripts, a 1.6 kb transcript which corresponds to the predicted size of the gene, and a second transcript, 3.5 kb, which also overlaps virR. These results demonstrate that virR and mry are structurally and functionally very similar and show that the former is a trans activator of both M protein and C5a peptidase synthesis.
Mol
Gen Genet 1993 Dec
PMID:VirR and Mry are homologous trans-acting regulators of M protein and C5a peptidase expression in group A streptococci. 750 89
Similar folds often occur in proteins with dissimilar sequences. The OB-fold forms a part of the structures of at least seven non-homologous proteins that share either oligonucleotide or oligosaccharide binding functions.
A 1
-103 fragment corresponding to the OB-fold of the 149 amino acid residue staphylococcal nuclease gives NMR spectra characteristic of an unfolded protein, i.e. the wild-type nuclease sequence is insufficient to maintain a stable tertiary structure in the absence of the C-terminal one-third of this single-domain protein. By contrast, the 1-103 fragment of nuclease with the mutations Val66Leu and Gly88Val adopts a stable tertiary structure. The NMR solution structure of this latter fragment is a close variation of the OB-fold found in the X-ray structure of the parent protein. The Val66Leu and Gly88Val mutations appear to stabilize tertiary structure by consolidating the hydrophobic core of the nuclease OB-fold sub-domain. Taken together, these results suggest that recurrent structural motifs such as the OB-fold may in some cases represent vestiges of autonomous folding units that, during evolution, have become integrated into more complex cooperative folding domains.
J
Mol
Biol 1995 Jul 07
PMID:NMR structure of a stable "OB-fold" sub-domain isolated from staphylococcal nuclease. 760 66
A 1
.2 kb DNA sequence, flanked by a potential seven base target-site duplication, was found inserted into a TOC1 transposable element from Chlamydomonas reinhardtii. The insertion sequence, named TOC2, is a member of a family of repeated DNA sequences that is present in all the C. reinhardtii strains tested. It resembles class II transposable elements: it possesses short 14 bp imperfect terminal repeats that begin AGGAGGGT, and sub-terminal direct repeats located within 250 bp of the termini. No large open reading frames were found. The terminal bases and length of target-site duplication are important in classifying transposable elements. On this basis TOC2 does not fall readily into existing families of class II transposable elements found in plants.
Plant
Mol
Biol 1995 Jun
PMID:A transposon-like sequence with short terminal inverted repeats in the nuclear genome of Chlamydomonas reinhardtii. 763 14
The chymotrypsin in the midgut of Manduca sexta has been purified, characterized and the cDNA encoding the protein has been cloned. The enzyme exists as a monomer of approx. 24 kDa and shows maximal activity between pH 10.5 and 11.0. Kinetic studies reveal that the Michaelis constant (Km) for the synthetic substrate N-succinyl-Ala-Ala-Pro-Phe p-nitroanilide varies only slightly between pH 7.5 and 11.5 and the Dixon plot shows a kinetically significant pKa at 9.2. The specificity of the purified enzyme was determined to be the peptide bond on the carboxyl side of tyrosine, phenylalanine, tryptophan, histidine, leucine, threonine and glycine. The protease is inhibited by TPCK, PMSF, chymostatin and DFP.
A 1
kilobase chymotrypsin cDNA clone was isolated and sequenced. The cDNA sequence encodes a preproenzyme with a putative 17 amino acid signal sequence, a 41 amino acid activation peptide and a mature enzyme of 235 amino acids. The isolated clone encodes the highly conserved active site residues (His, Asp, Ser) and specificity pocket residues present in bovine chymotrypsinogen B. Northern analysis localizes the mRNA for the chymotrypsin to the anterior and middle third of the midgut.
Insect Biochem
Mol
Biol 1995 Jul
PMID:Purification, characterization and cDNA sequence of an alkaline chymotrypsin from the midgut of Manduca sexta. 763 64
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