par Maenhaut, Geneviève 
;Blake, Catherine C.E.;Leach, David R F;Shapiro, James A.James
Référence Molecular microbiology, 23, 6, page (1133-1145)
Publication Publié, 1997
;Blake, Catherine C.E.;Leach, David R F;Shapiro, James A.JamesRéférence Molecular microbiology, 23, 6, page (1133-1145)
Publication Publié, 1997
Article révisé par les pairs
| Résumé : | Formation of araB-lacZ coding-sequence fusions is a key adaptive mutation system. Eighty-four independent araB-lacZ fusions were sequenced. All fusions carried rearranged MuR linker sequences between the araB and lacZ domains indicating that they arose from the standard intermediate of the well-characterized Mu DNA rearrangement process, the strand transfer complex (STC). Five non-standard araB-lacZ fusions isolated after indirect sib selection had novel structures containing back-to-back inverted MuR linkers. The observation that different isolation procedures gave rise to standard and non-standard fusions indicates that cellular physiology can influence late steps in the multi-step biochemical sequence leading to araB-lacZ fusions. Each araB-lacZ fusion contained two novel DNA junctions. The MuR-lacZ junctions showed 'hot-spotting' according to established rules for Mu target selection. The araB-MuR and MuR-MuR junctions all involved exchanges at regions of short sequence homology. More extensive homology between MuR and araB sequences indicates potential STC isomerization into a resolvable four-way structure analogous to a Holliday junction. These results highlight the molecular complexity of araB-lacZ fusion formation, which may be thought of as a multi-step cell biological process rather than a unitary biochemical reaction. |
