Gene
The energy-dependent efflux of erythromycin (Er) in staphylococci is due to the presence of msrA, which encodes an ATP-binding protein. MsrA is related to the multi-component ATP-binding cassette (ABC) transporters which characteristically also contain membrane-spanning domains. Since MsrA functions in a heterologous host in the absence of other plasmid-encoded products, the requirement for a transmembrane...
The nucleotide sequence of a 2.7-kb region of Clostridium acetobutylicum ATCC 824 DNA containing three open reading frames was determined. They encoded homologs of three proteins of Bacillus subtilis, and the gene arrangement in both organisms was identical. The first gene, orfA, was 801-bp long; the 31-kDa (266 aa) product it encoded exhibited homology with the putative σ E -processing...
Exchange of nucleotide (nt) sequences between the catIJF and pcaIJF regions of the Acinetobacter calcoaceticus chromosome appears to contribute to frequent repair of mutations, including removal of a Tn5 insertion from pcaJ. Repaired nt sequences are the products of nonreciprocal genetic exchange. The length of donor catIJF nt tracts recovered in repaired pcaIJF DNA ranged from less than 315 nt...
PCR was used to amplify approx. 1470-bp segments of DNA containing complete Shiga-like toxin type I (sltI) operons from Escherichia coli strains belonging to serotypes O48:H21, O111:H - and OX3:H8. These fragments were cloned and DNA sequence analysis identified several variations, as compared with published sltI sequences. All three sltI genes analysed were more closely related to Shiga...
The nucleotide (nt) sequence of the Streptomyces hygroscopicus gene encoding carboxyphosphonoenolpyruvate (CPEP) synthase, that catalyzes a transesterification between phosphoenolpyruvate (PEP) and phosphonoformate (PF) in the bialaphos biosynthetic pathway, has been determined. The amino-acid sequence deduced from the nt sequence is similar to several eukaryotic 2-phospho-d-glycerate hydrolases...
Nucleotide sequencing revealed the gene (axeA) encoding acetyl xylan esterase (AxeA) downstream from xlnB in theStreptomyces lividans DNA insert of plasmid pIAF42. AxeA consists of a catalytic- and a substrate-binding domain separated by a Gly-rich linker. The N terminus showed no significant homology with published esterases and acetyl xylan esterases, but some homology was found with the xylanases...
We have isolated a number of porphyrin (Por)-synthesis mutants as light-resistant revertants of a light-sensitive strain ΔvisA (hemH) of Escherichia coli that accumulates protoPor IX in the cell. Among such mutants, we found a double mutant (H103) with mutations in hemA and in a new gene downstream of hemA. This new gene, designated hemK, was located at 27 min on the linkage map of the E. coli chromosome...
A 547-bp group-I intron belonging to subgroup IA1 was found near the 3 end of the large subunit ribosomal RNA-encoding gene (LSUrRNA) in the mitochondrial (mt) DNA of the cellular slime mold Dictyostelium discoideum. This intron was inserted in a highly conserved stretch within the sequence that encodes the peptidyl transferase center domain V in the corresponding region of the Escherichia coli...
The nucleotide (nt) sequence of the Helicobacter pylori (Hp) napA gene, encoding neutrophil-activating protein A (HPNAP) was determined. Alignment of this sequence with those of known bacterioferritins (Bfr) revealed sequence homology and conservation of a 7-amino-acid (aa) motif constituting the ferroxidase (Frx) center of Bfr in the HPNAP. The N-terminal aa sequence deduced from the iron-regulated...
We have constructed two expression vectors based on the pJF118HE vector developed for Escherichia coli by Furste et al. [Gene 48 (1986) 119-131]. The tac promoter (ptac) was exchanged for the trc promoter (ptrc) and anNde I site was created at the appropriate distance from the ribosome-binding site. The NdeI site permits cloning of a gene at its translation start point without altering the amino-acid...
The pMDS series of cloning vectors developed for use in halophilic archaea have utilized a 10.5-kb plasmid, pHK2, from Haloferax sp. Aa2.2. The minimal replicon of pHK2 has now been determined (3359 bp) and completely sequenced. No significant sequence similarity was found between the pHK2 subfragment and plasmid pHV2 from the closely relatedH. volcanii . However, a long open reading frame (ORF),...
A DNA fragment encoding the DNA-binding domain (amino acids 1-60) of the Escherichia coli fru transcriptional regulator was cloned into the pGEX-KT vector and expressed in frame with the fused gene encoding glutathione S-transferase. The fusion protein was purified to homogeneity by affinity chromatography on immobilized glutathione, and then cleaved with thrombin. After separation by a cation-exchange...
In an effort to identify amino acid (aa) residues near the active site of TaqI restriction endonuclease (ENase), a sequence-specific photoaffinity reagent was designed. This reagent exploits the finding that modification of the R p oxygen of the scissile phosphate does not interfere with substrate binding. The TpCGA phosphate was substituted with an R p phosphorothioate group to...
A 6.3-kb DNA fragment encoding two eukaryotic-type serine/threonine protein kinases (Ser/Thr PK) was cloned from Streptomyces coelicolor A3(2) by using a PCR product obtained with primers based on highly conserved regions of eukaryotic Ser/Thr PK. The nucleotide (nt) sequence of the essential 4.4-kb fragment contained two possible ORFs. One ORF (PkaA) contained 543 amino acids (aa), while another...
Three genes (hrd) homologous to the rpoD gene of Escherichia coli, that encode sigma factor-like proteins, have been cloned from DNA of the candicidin-producing strain Streptomyces griseus IMRU 3570. They are located in different regions of the chromosome. Sequence analysis showed that the first one is analogous to the hrdB gene of S. coelicolor. The second showed high similarity to the hrdD gene...
Pseudomonas syringae pv. glycinea PG4180 produces the chlorosis-inducing phytotoxin coronatine (COR), which consists of a polyketide component, coronafacic acid (CFA), ligated by an amide bond to coronamic acid (CMA), an ethylcyclopropyl amino-acid derived from isoleucine. We report the nucleotide sequence of a 2.37-kb region containing the coronafacate ligase-encoding gene (cfl) which is required...
The pho-5 + gene of Neurospora crassa, which encodes a high-affinity phosphate permease, has been cloned and analyzed. The deduced ORF of 1707 nucleotides is interrupted by a single 63-nt intron and codes for a protein of 569 amino acids (aa). This aa sequence has 48% identity with the high-affinity phosphate transporter of Saccharomyces cerevisiae, PHO84. The pho-5 null mutants have no...
The Vibrio cholerae (Vc) gene (tagA) coding for the TagA lipoprotein has been isolated. Sequencing of tagA revealed the presence of an open reading frame (ORF) of 568 amino acids with a characteristic signal peptidase II cleavage site at the N terminus. Electrophoretic analysis of proteins synthesized by Escherichia coli (Ec) cells following T7 promoter/RNA polymerase-directed expression of tagA,...
A new mobilizable cosmid vector, pCOS5, was engineered for use in Vibrio cholerae (Vc). Plasmid pCOS5 is small in size (7286 bp), contains the oriT from plasmid RK2, and has several unique restriction sites. The complete nucleotide sequence of pCOS5 was deduced from the DNA fragments used in its construction. Biparental matings using Escherichia coli (Ec) SM10 and triparental matings using Ec DH5α[pRK2013]...
Pectinases produced by Aspergillus flavus and A. parasiticus are believed to play a significant role in the ability of these fungi to spread in cotton bolls and other crops. Utilizing a DNA probe, generated by PCR, of the Aspergillus niger pgaII gene, we have isolated a novel, constitutively expressed polygalacturonase (PG)-encoding gene (pecA) from an A. parasiticus cDNA library. DNA sequence analysis...