Disease relevance of trpB

• Nucleotide sequence of the trpB gene in Escherichia coli and Salmonella typhimurium [1].
• The Pseudomonas aeruginosa tryptophan synthase genes, trpA and trpB, which are induced by their substrate indoleglycerol phosphate, were cloned along with their controlling region into the BamHI site of pBR322 to produce the 10.7-megadalton plasmid pZAZ5 [2].
• This indicated that commensal Neisseria species share a possible integration site for the iga gene between comA and trpB [3].
• In contrast to all other prokaryotes, Synechocystis has a trpB gene that is monocistronic [4].

High impact information on trpB

• Transformants were obtained by electroporation of a plasmid, called SAG1/trpB, containing the trpB gene flanked by Toxoplasma surface antigen 1 (SAG1) gene sequences and selection for growth on indole [5].
• Transformation with either circular or linear SAG1/trpB resulted in integration into the genome at distinct, nonhomologous sites [5].
• Complementation was accomplished by expressing the Escherichia coli trpB gene, encoding the beta subunit of tryptophan synthase (EC 4.2.1.20), the enzyme that catalyzes the formation of tryptophan from indole plus serine [5].
• Expression of the trpB gene of Escherichia coli, which encodes the beta subunit of tryptophan synthase (EC 4.2.1.20), allows mammalian cell survival and multiplication in medium containing indole in place of tryptophan [6].
• Translation of trpB is terminated by single UGA codon, which overlaps the trpA AUG initiation codon: UGAUG [7].

Chemical compound and disease context of trpB

• The trpB and trpA coding regions of the polycistronic trp mRNA of Escherichia coli are separated by overlapping translation stop and start codons [8].

Biological context of trpB

• Most of the nucleotide sequences can be assigned to specific locations in the structural genes, based on the amino-acid sequences of the trpB and trpA proteins [7].
• The resulting phylogeny was congruent with trees derived from sequences of two chromosome-located bacterial genes (part of trpB and 16S ribosomal DNA) [9].
• This modification avoids the polar effects encountered when either an untranslated sequence, or a sequence translated in a different reading frame is fused to trpB [10].
• The expression of the trpB gene was remarkably enhanced (>12-fold) by the introduction of an overlapping leader open reading frame [11].
• Transformants were obtained with circular forms of the SAG1/trpB plasmid with efficiencies of 10(-4) per cell [5].

Associations of trpB with chemical compounds

• The trpA and trpB genes encoding the tryptophan synthase subunits were cloned from the hyperthermophilic archaeon Pyrococcus furiosus [11].
• The trp poL was used successfully to control the expression of lac alpha, luxAB, trpB and trpA [12].

Other interactions of trpB

• In N. gonorrhoeae, the genes trpB and ksgA were found immediately downstream of iga [3].

Analytical, diagnostic and therapeutic context of trpB

• The polymerase chain reaction (PCR) was applied to clone the luxA and luxB genes from Vibrio harveyi, and the trp poL (promoter operator leader) region and the trpB and trpA genes from Escherichia coli [12].
• Southern and northern blotting analyses suggest that Synechocystis contains only a single trpB gene [4].

References