Disease relevance of int

• Lambda's int gene contains an anomalously high frequency of the rare arginine codons AGA and AGG when compared to genes of Escherichia coli or to the rest of phage lambda [1].
• Retroregulation of int is caused, in part, by processing of the pL transcript at the sib site by RNase III of Escherichia coli [2].
• Plasmids pSPRH840 and pSPRH910, containing the pMLP1 att/int region, were introduced into Micromonospora spp. by conjugation from Escherichia coli [3].
• We demonstrate that the site-specific integrase encoded by phage TP901-1 of Lactococcus lactis subsp. cremoris has potential as a tool for engineering mammalian genomes [4].

High impact information on int

• This region also contains an open reading frame homologous to one present in Tn1696 (member of the Tn21 family) which encodes a site-specific integrase [5].
• To facilitate the study of the attB site, the int and xis genes, expressed from an inducible promoter, and attP from pSAM2 were cloned on plasmids in Escherichia coil [6].
• In this study, we show that expression of the natural int gene may also be modulated by rare arginine codon usage, and we explore this mechanism [1].
• Both sib+ and sib- deletions were sequenced, and it was concluded from this and other work that a dyad symmetry present in the b region, 270 base-pairs from int, was necessary for retroregulation [2].
• The lambda int gene product, integrase, recombines phage and bacterial DNA at a specific site during the integration step of lysogeny [2].

Biological context of int

• Sequence analysis revealed the presence of an IS1 element between the int gene and the afa-3 gene cluster [7].
• Plasmids containing the site-specific att/int functions of pMLP1 can be used to integrate genes into the chromosome [3].
• DNAs homologous to bacteriophage int and attP were located upstream of gtrA(IV), suggesting that this region of the NCTC 8296 genome may have originated from a bacteriophage; however, a serotype-converting phage could not be induced from this strain nor from other strains used in this study [8].

Other interactions of int

• The authors report here that phage Phi42 encodes a restriction-modification (R-M) system, termed Sau42I, adjacent to and in the same orientation to the phage integrase gene int [9].

References