RTP and Tus: Difference between revisions
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The Replication Terminator Protein (RTP) from ''Bacillus subtilis'' is comprised of two identical monomers 14.5 kDa in size which bind to DNA to form a homodimer. The separate monomers bind at 30 bp sequences known as the A and B termination (Ter) sites. Both of these sites have inverted 16 bp repeats which overlap at highly conserved TAT trinucleotide sequence. The structure of RTP is commonly referred to as a “winged helix” DNA binding motif and consists of a compact α helix / β-strand <scene name='RTP_and_Tus/Practice_structure/5'>secondary structure</scene> with a protruding loop (or “wing”) between the β2 and β3 strands. Both monomers of RTP interact with DNA specifically through hydrogen bonding at residues | The Replication Terminator Protein (RTP) from ''Bacillus subtilis'' is comprised of two identical monomers 14.5 kDa in size which bind to DNA to form a homodimer. The separate monomers bind at 30 bp sequences known as the A and B termination (Ter) sites. Both of these sites have inverted 16 bp repeats which overlap at highly conserved TAT trinucleotide sequence. The structure of RTP is commonly referred to as a “winged helix” DNA binding motif and consists of a compact α helix / β-strand <scene name='RTP_and_Tus/Practice_structure/5'>secondary structure</scene> with a protruding loop (or “wing”) between the β2 and β3 strands. Both monomers of RTP interact with DNA specifically through hydrogen bonding at residues | ||
<scene name='RTP_and_Tus/Practice_structure/7'>Arg 59, His 54 and Thr 55, and also through nonbonding contacts with Tyr 58</scene>. RTP also forms non-specific interactions at its N-terminus region.<ref>Wilce JA, Vivian JP, Hastings AF, Otting G, Folmer RHA, Duggin IG, Wake RG, Wilce MCJ (2001) Structure of the RTP-DNA complex and the mechanism of polar replication fork arrest. ''Nature Structural Biology'' 8: 206-210.</ref> | <scene name='RTP_and_Tus/Practice_structure/7'>Arg 59, His 54 and Thr 55, and also through nonbonding contacts with Tyr 58</scene>, present in the α3 recognition helix. RTP also forms non-specific interactions at its N-terminus region.<ref>Wilce JA, Vivian JP, Hastings AF, Otting G, Folmer RHA, Duggin IG, Wake RG, Wilce MCJ (2001) Structure of the RTP-DNA complex and the mechanism of polar replication fork arrest. ''Nature Structural Biology'' 8: 206-210.</ref> | ||
The first crystal structure of RTP was determined in 1995 by Bussiere ''et al.'' (See figure above).<ref>Bussiere DE, Bastia D, White SW (1995) Crystal structure of the replication terminator protein from ''B. subtilis'' at 2.6 A. ''Cell'' 80(4): 651-60.</ref> This initial structure, which used a symmetric B ''Ter'' DNA homologue, suggested that the RTP exists as a symmetric homodimer. The idea that a symmetric protein structure could be responsible for an inherently polar mechanism has resulted in a series of proposed solutions and discoveries regarding the mechanism of replication fork arrest. | The first crystal structure of RTP was determined in 1995 by Bussiere ''et al.'' (See figure above).<ref>Bussiere DE, Bastia D, White SW (1995) Crystal structure of the replication terminator protein from ''B. subtilis'' at 2.6 A. ''Cell'' 80(4): 651-60.</ref> This initial structure, which used a symmetric B ''Ter'' DNA homologue, suggested that the RTP exists as a symmetric homodimer. The idea that a symmetric protein structure could be responsible for an inherently polar mechanism has resulted in a series of proposed solutions and discoveries regarding the mechanism of replication fork arrest. | ||
