Disease relevance of attB

• We report that transformation of Streptomyces lividans with cloned DNA of the SLP1 genetic element results in integration of the element at the same chromosomal locus (attB) normally occupied by SLP1 in its original host, Streptomyces coelicolor, and in S. lividans that has received SLP1 by mating [1].
• We note here that these two putative tRNA genes as well as those which overlap the attB site of the elements SLP1 of Streptomyces coelicolor and pMEA100 of Nocardia mediterranei all contain the site where integrative recombination takes place [2].
• Southern hybridization analysis showed that sequences similar to the pSAM2 attB site were found in other actinomycetes (Mycobacterium, Nocardia, Micromonospora) as well as unrelated bacteria (Bacillus circulans, Escherichia coli, Clostridium botulinum, Bordetella pertussis, and Legionella pneumophila) [2].

High impact information on attB

• The requirement for this tRNA gene has been used to stabilize the inheritance of a segrationally unstable plasmid in cells lacking a chromosomal attB site [3].
• We demonstrate here by means of gene replacement that a tRNA(Tyr) sequence that overlaps part of the attB site of S. lividans is both biologically functional and essential for cell viability [3].
• We constructed SLP1 derivatives that can integrate foreign DNA at the attB site and used these to introduce adventitious DNA sequences into the S. lividans chromosome [1].
• The pSAM2 element of Streptomyces ambofaciens integrates site-specifically in the genome of different Streptomyces species by recombination between a 58 bp sequence common to the plasmid (attP) and the chromosome (attB) [2].
• The conserved region contained an open reading frame (ORF A) with a stop codon located 99 bp from the attB sequence in both strains [4].

References