Sandbox 666: Difference between revisions
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Journal: (1990) Science 249: 1307-1309 </ref> | Journal: (1990) Science 249: 1307-1309 </ref> | ||
In the old model the N-terminal section of each subunit forms the inner arm which wraps around the DNA molecule (The arm brings the DNA molecule to the catalytic cleft.).The new chain tracing, based on new elements of electron density and a new interpretation that alters the assignment of specific amino acid residues to some of the original features<ref name="B" />. In the new model,the Inner arm is the extended chain motif (Met<sup>137</sup>to Ala<sup>142</sup>)is a segment of extended polypeptide chain that runs through the major groove of the DNA, roughly parallel to the DNA backbone<ref name="B" />. The outer arm is composed of two minor β strands linked together by a loop (the outer arm is 14 amino acids long, four of these amino acids belong to the loop). | In the old model the N-terminal section of each subunit forms the inner arm which wraps around the DNA molecule (The arm brings the DNA molecule to the catalytic cleft.).The new chain tracing, based on new elements of electron density and a new interpretation that alters the assignment of specific amino acid residues to some of the original features<ref name="B" />. In the new model,the Inner arm is the extended chain motif (Met<sup>137</sup>to Ala<sup>142</sup>)is a segment of extended polypeptide chain that runs through the major groove of the DNA, roughly parallel to the DNA backbone<ref name="B" />. The outer arm is composed of two minor β strands linked together by a loop (the outer arm is 14 amino acids long, four of these amino acids belong to the loop). | ||
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This binding by the major groove is due to the position of scissile phosphodiester bonds.<ref name="A">Recognition and cleavage of DNA by type-II restriction endonucleases, Pingoud A. & Jeltsch A. Eur.J.Biochem. 246,1-22 (1997)</ref> | This binding by the major groove is due to the position of scissile phosphodiester bonds.<ref name="A">Recognition and cleavage of DNA by type-II restriction endonucleases, Pingoud A. & Jeltsch A. Eur.J.Biochem. 246,1-22 (1997)</ref> | ||
[[Image:Catalytic 1ERI.png | thumb | The catalytic core of Eco RI with the target DNA|left| | {| | ||
| [[Image:Catalytic 1ERI.png | thumb | The catalytic core of Eco RI with the target DNA|left|395px]] | |||
| [[Image:Image1 EcoRI.png |thumb| The topology of EcoRI restriction endonuclease<ref name="A" />|right|385px]] | |||
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==Catalytic mechanism== | ==Catalytic mechanism== | ||
