Disease relevance of entB

• Nucleotide sequence and transcriptional organization of the Escherichia coli enterobactin biosynthesis cistrons entB and entA [1].

High impact information on entB

• The deduced amino acid sequence of venB is 41% identical to the enzyme isochorismatase of Escherichia coli (EntB), an enzyme involved in the biosynthesis of the catechol siderophore enterobactin [2].
• Subcloning of the enterobactin biosynthetic gene entB: expression, purification, characterization, and substrate specificity of isochorismatase [3].
• The resulting recombinant plasmid pFR1 expresses isochorismatase amounting to over 50% of the total cellular protein [3].
• Four closely linked open reading frames, corresponding to the coding regions of entE (carboxy-terminal 144 amino acids), entB (32,554 daltons), entA (26,249 daltons), and an unidentified gene (P15) encoding a 14,970-dalton protein, were found [4].
• The closest sequence homologs with an assigned function belong to a family of bacterial hydrolases that catalyze isochorismatase-like reactions, but these have only low sequence similarity to ycaCgp (approximately 20% amino acid identity) [5].

Biological context of entB

• The sequence revealed that an independent protein-coding sequence corresponding to an EntG polypeptide was not situated in the genetic region between the entB and entA cistrons, to which the EntG- phonotype had been genetically localized [1].
• The nucleotide sequence of a 2,137-base-pair DNA fragment expressing enterobactin biosynthesis functions defined the molecular boundaries and translational products of the entB and entA genes and identified a closely linked downstream open reading frame encoding an uncharacterized protein of approximately 15,000 daltons (P15) [1].

References