2mqk

Structural highlights

Function

TARGB_BPMU Selects the target DNA sites for transposition. Recruits DDE-recombinase A to the target sites and catalytically activates it. Displays non-specific DNA-binding properties. Polymerizes as helical filaments around the DNA. Coating of the DNA by the target DNA activator B might play a role in favoring target-primed replication over integration. Prevents self-integration into an integrated copy of the viral genome. This mechanism is called target immunity and is achieved by two mechanisms: first, the target DNA activator B dissociates from the viral genome ends upon interaction in cis with DDE-recombinase A, which makes the viral genome ends a poor target for new insertions. Second, the interior of the viral genome may also ne protected from integration events by the target DNA activator B being strongly bound throughout the whole viral genome.^{[1] [2] [3] [4] [5] [6] [7] [8]}

References

1. ↑ Roldan LA, Baker TA. Differential role of the Mu B protein in phage Mu integration vs. replication: mechanistic insights into two transposition pathways. Mol Microbiol. 2001 Apr;40(1):141-55. PMID:11298282
2. ↑ Goldhaber-Gordon I, Early MH, Baker TA. MuA transposase separates DNA sequence recognition from catalysis. Biochemistry. 2003 Dec 16;42(49):14633-42. PMID:14661976 doi:http://dx.doi.org/10.1021/bi035360o
3. ↑ Baker TA, Mizuuchi M, Mizuuchi K. MuB protein allosterically activates strand transfer by the transposase of phage Mu. Cell. 1991 Jun 14;65(6):1003-13. PMID:1646076
4. ↑ Tan X, Mizuuchi M, Mizuuchi K. DNA transposition target immunity and the determinants of the MuB distribution patterns on DNA. Proc Natl Acad Sci U S A. 2007 Aug 28;104(35):13925-9. Epub 2007 Aug 20. PMID:17709741 doi:http://dx.doi.org/10.1073/pnas.0706564104
5. ↑ Lemberg KM, Schweidenback CT, Baker TA. The dynamic Mu transpososome: MuB activation prevents disintegration. J Mol Biol. 2007 Dec 14;374(5):1158-71. Epub 2007 Oct 3. PMID:17988683 doi:http://dx.doi.org/10.1016/j.jmb.2007.09.079
6. ↑ Ge J, Lou Z, Harshey RM. Immunity of replicating Mu to self-integration: a novel mechanism employing MuB protein. Mob DNA. 2010 Feb 1;1(1):8. doi: 10.1186/1759-8753-1-8. PMID:20226074 doi:http://dx.doi.org/10.1186/1759-8753-1-8
7. ↑ Mizuno N, Dramicanin M, Mizuuchi M, Adam J, Wang Y, Han YW, Yang W, Steven AC, Mizuuchi K, Ramon-Maiques S. MuB is an AAA+ ATPase that forms helical filaments to control target selection for DNA transposition. Proc Natl Acad Sci U S A. 2013 Jun 17. PMID:23776210 doi:10.1073/pnas.1309499110
8. ↑ Dramicanin M, Ramon-Maiques S. MuB gives a new twist to target DNA selection. Mob Genet Elements. 2013 Sep 1;3(5):e27515. Epub 2013 Dec 12. PMID:24478936 doi:http://dx.doi.org/10.4161/mge.27515