Disease relevance of astA

• The isolates harbouring these genes were also tested using the HEp-2 cell-adhesion assay to clarify their EAEC status. aat, aai or astA was found in E. coli faecal isolates from 39 (7.8 %) of 500 patients, and 20 of these strains adhered to HEp-2 cells in a pattern characteristic of EAEC [1].
• Transposition of the heat-stable toxin astA gene into a gifsy-2-related prophage of Salmonella enterica serovar Abortusovis [2].
• The probe (1.5 kb fragment) for the astA gene was prepared from the PCR product of the primers produced using two internal amino acid sequences of ASST, which had been purified from Eubacterium A-44 [3].
• Cloning and characterization of the aru genes encoding enzymes of the catabolic arginine succinyltransferase pathway in Pseudomonas aeruginosa [4].

High impact information on astA

• Here we report the crystal structure of N-succinylarginine dihydrolase AstB, the second enzyme of the arginine succinyltransferase pathway, providing the first structural insight into enzymes from this pathway [5].
• The ammonia-producing arginine succinyltransferase pathway is the major pathway in Escherichia coli and related bacteria for arginine catabolism as a sole nitrogen source [5].
• The changes in the blood packed-cell volume and plasma total protein of gnotobiotic piglets inoculated with the LT-positive strains were significantly greater than those of pigs inoculated with the K88 astA/pBR322 strain (P = 0.012, P = 0.002) [6].
• Biofilm formation was measured by using a microtiter plate assay with the crystal violet staining method, and the presence of the putative EAEC virulence genes aap, aatA, aggR, astA, irp2, pet, set1A, and shf was determined by PCR [7].
• Transformation experiments confirmed statistical associations by demonstrating that elt, estB, astA, aadA and sul1 were located with catA1 on a large ETEC plasmid [8].

Chemical compound and disease context of astA

• Arginine catabolism and the arginine succinyltransferase pathway in Escherichia coli [9].
• We conclude that the AST pathway is necessary for aerobic arginine catabolism in E. coli and that at least one enzyme of this pathway contributes to ornithine catabolism [9].
• A gene (astA) encoding arylsulfate sulfotransferase (ASST), which transfers a sulfate group from phenolic sulfate esters to phenolic acceptors, was cloned from a Eubacterium A-44 genomic library [3].

Biological context of astA

• Eight isolates carrying the aai or astA gene but not the aat gene were shown to be HEp-2 cell test positive, although 12 strains with this genotype were HEp-2 cell test negative [1].
• We identified the E. coli gene for succinylornithine aminotransferase, the third enzyme of the AST pathway, which appears to be the first of an astCADBE operon [9].
• The EAEC heat-stable enterotoxin 1 gene, astA, was found in 14% (10/72) of the ECOR strains and a consensus sequence for astA was proposed by comparing these sequences with those from pathogens [10].
• Half of the CDEC isolates had enteroaggregative DNA sequences (pet, astA, aggA), six strains carried the shet1 gene, nine strains carried the daaC sequence, and one strain carried the stp gene [11].
• The deduced amino acid sequences of the AST enzymes were compared to those of homologous proteins of Escherichia coli specified by the ast genes lying in the chromosome region from 39.2 to 39.5 min (Kohara clone 327; GenBank/EMBL/DDJB accession no. D90818) [4].

Associations of astA with chemical compounds

• Overproduction of AST enzymes resulted in faster growth with arginine and aspartate [9].
• Its disruption prevented arginine catabolism, impaired ornithine utilization, and affected the synthesis of all the enzymes of the AST pathway [9].

Enzymatic interactions of astA

• Arginine succinyltransferase and succinylarginine dihydrolase catalyze the first two steps of arginine catabolism by the arginine succinyltransferase pathway [12].

Other interactions of astA

• Using the HEp-2 adhesion assay as the gold standard, the addition of primers detecting aaiA and astA to the aat PCR increased the number of EAEC isolates detected, but identified strains of E. coli that were not EAEC [1].

References