Disease relevance of ORF2

• It shows 45% amino acid residue identity with open reading frame ORF2 of pSR1, a plasmid isolated from Corynebacterium glutamicum (J. A. C. Archer and A. J. Sinskey, J. Gen. Microbiol. 139:1753-1759, 1993) [1].
• The amino acid sequences deduced from ORF1 and ORF2 display strong homologies to those of the alpha- and beta-subunits of the Bacillus subtilis aspartokinase II [2].

High impact information on ORF2

• ORF2, which uses the same reading frame as ORF1, is identical to the 3' end of ORF1 and encodes a putative protein of 172 amino acids (aa) and of Mr 18,584 [2].
• ORF2 is responsible for AEC resistance and lysine production due to a feedback-resistant aspartokinase [2].
• A DNA-sequence analysis of the cloned DNA identified two open-reading frames (ORFs) of ORF1 and ORF2 that consisted of 1,107 and 978 bp, respectively [3].
• ORF2 (position 1633-2636) with a maximum coding potential of 36 kDa is essential for pSR1 replication and was designated the rep gene [4].
• The predicted ORF2 protein product exhibits 47% identity over a length of 343 amino acids with a replication-associated ORF in the C. diphtheriae plasmid pNG2, many of the changes being in the third base position [4].

Biological context of ORF2

• This region contains a single large open reading frame, ORF2, flanked at the 5' end by a series of inverted repeat sequences which may modulate its expression, and at the 3' end by a region which may contain a replication origin [4].

References