Sand box 211: Difference between revisions
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{{STRUCTURE_1exn| PDB=1exn | SCENE=Celina_Pinto/Sandbox_211/Chaina_b/1 }} | |||
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The T5 5'-exonuclease is found in bacteriophages T5 and is coded by the gene D15 | The T5 5'-exonuclease is found in bacteriophages T5 and is coded by the gene D15. It is called metalloenzyme because it has binding sites for divalent metal ions without which the enzyme isn't able to cut DNA. However, it can bind to DNA without binding a divalent metal ion. | ||
== '''Activity''' == | == '''Activity''' == | ||
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<Structure load='1EXN' size='500' frame='true' align='right' caption='T5 5'exonuclease' scene='Insert optional scene name here' /> | <Structure load='1EXN' size='500' frame='true' align='right' caption='T5 5'exonuclease' scene='Insert optional scene name here' /> | ||
<scene name='Sand_box_211/1exn/2'>T5 5'- | <scene name='Sand_box_211/1exn/2'>T5 5'-exonuclease</scene> is a homodimeric protein composed of two identical chains, <scene name='Sand_box_211/Vghjvjh/2'>chain a</scene> and <scene name='Sand_box_211/Vhj/1'>chain b</scene>. | ||
Both chains contain a hole, bound by a helical arch composed of two helices in which hydrophobic and positively charged residues are located. The helical arch is situated in front of the active site and only single-stranded DNA can pass through it. Since the enzyme is able to cleave double-stranded DNA, the enzyme has a conformational flexibility to facilitate DNA threading which is required to process the 5' nuclease substrates in the active site. | Both chains contain a hole, bound by a helical arch composed of two helices in which hydrophobic and positively charged residues are located. The helical arch is situated in front of the active site and only single-stranded DNA can pass through it. Since the enzyme is able to cleave double-stranded DNA, the enzyme has a conformational flexibility to facilitate DNA threading which is required to process the 5' nuclease substrates in the active site. | ||