High impact information on orf3

• However, a small but significant difference in virulence was observed between these two derivatives and the parental D39 strain in a low-dose intraperitoneal challenge model, suggesting that the ORF3 product may also contribute to pathogenesis [1].
• Five tetracycline-resistant isolates had no PCR evidence of orf1 and orf2 and showed variable patterns as to orf3, orf7, and orf8 [2].
• In an orf3-positive element, sequencing identified four new open reading frames downstream of the tet(O) gene, followed by three short sequences with homology to sequences of the pneumococcal mega element [3].
• Thus, ORF1, ORF2, and ORF3 are part of the ure operon, and these genes, designated ureM, ureQ, and ureO, respectively, likely encode a Ni(2+)-specific ATP-binding cassette transporter [4].
• ORF4 encodes for a protein highly homologous to orf3 of pVA380-1 of S. ferus, but its function is unknown [5].

Biological context of orf3

• The completed nucleotide base sequence of pVA380-1 revealed the presence of two additional open reading frames, ORF2 and ORF3 [6].
• The deduced amino acid sequence of one of these, ORF3, was found to be similar to that of several prokaryotic transcriptional regulator proteins [7].
• Gel mobility shift assays showed that the ORF3 protein was capable of binding to not only other discrete sites at the left end of the element but also its own promoter, suggesting autoregulation [7].
• The presence of a multicopy plasmid carrying ORF3 in a donor cell carrying Tn5252 with a mutated copy of ORF3 or an unaltered element also reduced the transfer frequency of the element similarly [7].

Other interactions of orf3

• There was no similarity between ORF3 and ORF6 and other protein sequences [5].

References