User:Nathan Harris/Tus: Difference between revisions

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=='''Biological role'''==

Multiple ''Ter'' sites (''TerA''- ''TerJ'') are located in regions destined for replication termination in ''E. coli''. Tus binds specifically to these 23bp ''Ter'' sites forming a Tus-''Ter'' complex. This complex allows for the blocking of an approaching replication fork in one direction, the non-permissive face, but not from the other direction, the permissive face. The ability to halt the replication machinery at the non-permissive face is thought to involve the inhibition of DnaB Helicase, preventing it from unwinding DNA. DnaB inhibition has been proposed to occur either through protein-protein interactions between Tus and DnaB, or by a physical block provided by Protein-DNA interactions i.e. the Tus-''Ter'' complex. Recent models suggest a potentially combination of these two mechanisms. Evolution of this termination system has allowed for efficient replication by ''E. coli'' as it prevents any over expenditure of energy or time. Different replication proteins have been found in other model organisms, such as RTP in ''Bacillus subtilis''. Despite similar biological roles of RTP and Tus they have significantly different structures.

Multiple ''Ter'' sites (''TerA''- ''TerJ'') are located in regions destined for replication termination in ''E. coli''. Tus binds specifically to these 23bp ''Ter'' sites forming a Tus-''Ter'' complex <ref name = "Neylon"> "Neylon" Neylon, C., Kralicek, A. V., Hill, T.M. and Dixon, N.E. (2005) Replication Termination in Escherichia coli: Structure and Antihelicase Activity of the Tus-Ter Complex. Microbiology and Molecular Biology, 69 (3): 501-526.

</ref>

. This complex allows for the blocking of an approaching replication fork in one direction, the non-permissive face, but not from the other direction, the permissive face. The ability to halt the replication machinery at the non-permissive face is thought to involve the inhibition of DnaB Helicase, preventing it from unwinding DNA. DnaB inhibition has been proposed to occur either through protein-protein interactions between Tus and DnaB, or by a physical block provided by Protein-DNA interactions i.e. the Tus-''Ter'' complex <ref name = "Neylon" />

. Recent models suggest a potentially combination of these two mechanisms. Evolution of this termination system has allowed for efficient replication by ''E. coli'' as it prevents any over expenditure of energy or time. Different replication proteins have been found in other model organisms, such as RTP in ''Bacillus subtilis''. Despite similar biological roles of RTP and Tus they have significantly different structures.

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=='''References'''==

Anderson, P., Griffith, A., Duggin, I. and Wake, R. (2000) Functional specificity of the replication fork-arrest complexes of Bacillus subtilis and Escherichia coli: significant specificity for Tus-Ter functioning in E.coli. Molecular Microbiology, 36 (6): 1327-1335.

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 =='''Biological role'''==
-Multiple ''Ter'' sites (''TerA''- ''TerJ'') are located in regions destined for replication termination in ''E. coli''. Tus binds specifically to these 23bp ''Ter'' sites forming a Tus-''Ter'' complex. This complex allows for the blocking of an approaching replication fork in one direction, the non-permissive face, but not from the other direction, the permissive face.  The ability to halt the replication machinery at the non-permissive face is thought to involve the inhibition of DnaB Helicase, preventing it from unwinding DNA. DnaB inhibition has been proposed to occur either through protein-protein interactions between Tus and DnaB, or by a physical block provided by Protein-DNA interactions i.e. the Tus-''Ter'' complex.  Recent models suggest a potentially combination of these two mechanisms. Evolution of this termination system has allowed for efficient replication by ''E. coli'' as it prevents any over expenditure of energy or time.  Different replication proteins have been found in other model organisms, such as RTP in ''Bacillus subtilis''.  Despite similar biological roles of RTP and Tus they have significantly different structures.
+Multiple ''Ter'' sites (''TerA''- ''TerJ'') are located in regions destined for replication termination in ''E. coli''. Tus binds specifically to these 23bp ''Ter'' sites forming a Tus-''Ter'' complex <ref name = "Neylon"> "Neylon" Neylon, C., Kralicek, A. V., Hill, T.M. and Dixon, N.E.  (2005) Replication Termination in Escherichia coli: Structure and Antihelicase Activity of the Tus-Ter Complex.  Microbiology and Molecular Biology, 69 (3): 501-526.
+</ref>
+. This complex allows for the blocking of an approaching replication fork in one direction, the non-permissive face, but not from the other direction, the permissive face.  The ability to halt the replication machinery at the non-permissive face is thought to involve the inhibition of DnaB Helicase, preventing it from unwinding DNA. DnaB inhibition has been proposed to occur either through protein-protein interactions between Tus and DnaB, or by a physical block provided by Protein-DNA interactions i.e. the Tus-''Ter'' complex <ref name = "Neylon" />
+.  Recent models suggest a potentially combination of these two mechanisms. Evolution of this termination system has allowed for efficient replication by ''E. coli'' as it prevents any over expenditure of energy or time.  Different replication proteins have been found in other model organisms, such as RTP in ''Bacillus subtilis''.  Despite similar biological roles of RTP and Tus they have significantly different structures.
@@ Line 54: / Line 57: @@
 =='''References'''==
+<references/>
 Anderson, P., Griffith, A., Duggin, I. and Wake, R.  (2000) Functional specificity of the replication fork-arrest complexes of Bacillus subtilis and Escherichia coli: significant specificity for Tus-Ter functioning in E.coli.  Molecular Microbiology, 36 (6): 1327-1335.