{"id":1010,"date":"2015-10-13T16:16:35","date_gmt":"2015-10-13T15:16:35","guid":{"rendered":"http:\/\/blogs.kent.ac.uk\/biosciences\/?p=1010"},"modified":"2018-09-20T10:01:52","modified_gmt":"2018-09-20T09:01:52","slug":"research-seminar-functional-coupling-of-duplex-translocation-to-dna-cleavage-in-a-type-i-restriction-enzyme","status":"publish","type":"post","link":"https:\/\/blogs.kent.ac.uk\/biosciences\/2015\/10\/13\/research-seminar-functional-coupling-of-duplex-translocation-to-dna-cleavage-in-a-type-i-restriction-enzyme\/","title":{"rendered":"Research Seminar: Functional coupling of duplex translocation to DNA cleavage in a type I restriction enzyme"},"content":{"rendered":"

Prof. RNDr. Rudiger Ettrich, <\/strong>C4SYS-Center for Systems Biology, Institute of Microbiology, Academy of Sciences of the Czech Republic <\/strong><\/p>\n

Tuesday 20th October, 1.00 p.m., Keynes Lecture Theatre 6<\/b><\/p>\n

Type I restriction-modification enzymes differ significantly from the type II enzymes commonly used as molecular biology reagents. On hemi-methylated DNAs type I enzymes act as conventional adenine methylases at specific target sequences, but unmethylated targets induce them to pull\u00a0thousands of basepairs through the stationary enzyme before it cleaves distant sites nonspecifically. Biochemical, biophysical, and molecular\u00a0biological studies of their translocation and cleavage mechanisms offer a wealth of detail that has lacked a structural framework. The crystal\u00a0structure, resolved at 2.6 \u00c5, of the motor subunit responsible for DNA translocation and cleavage by the type I enzyme EcoR124I shows a planar\u00a0array of four domains, and ATP-mediated contact between endonuclease and helicase domains that may couple cleavage and translocase activities\u00a0(1). Crystallography, point-mutations, and in vivo and in vitro assays in combination with computational modeling reveal how interdomain\u00a0engagement brings DNA cleavage under the control of translocation (2,3), and provide new general insights into type I restriction-modification\u00a0complexes.<\/p>\n

The proposed transport and regulatory mechanism provide new insights into the molecular basis of several human diseases caused by dysfunctional mitochondrial carriers.<\/p>\n

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  1. Mikalai Lapkouski, Santosh Panjikar, Pavel Janscak, Ivana Kuta Smatanova, Jannette Carey, R\u00fcdiger Ettrich, Eva Csefalvay (2009) Structure of the\u00a0motor subunit of type I restriction-modification complex EcoR124I. Nat Struct Mol Biol 16: 1. 94-95.<\/li>\n
  2. Eva Csefalvay, Mikalai Lapkouski, Alena Guzanova, Ladislav Csefalvay, Tatjana Baikova, Igor Shevelev, Vitali Bialevich,\u00a0Katsiaryna Shamayeva,\u00a0Pavel Janscak, Ivana Kuta Smatanova, Santosh\u00a0Panjikar, Jannette Carey, Marie Weiserova, R\u00fcdiger Ettrich (2015) Functional coupling of duplex translocation to DNA cleavage in a type I restriction\u00a0enzyme,\u00a0PLoS ONE\u00a010 (6):\u00a0\u00a0e0128700.<\/li>\n
  3. D Sinha, K Shamayeva, V Ramasubramani, D Reha, V Bialevich, M Khabiri, N Milbar, A Guzanova, M Weiserova, E Csefalvay, J Carey, R Ettrich(2014) Interdomain communication in the endonuclease\/motor subunit of Type I restriction-modification enzyme EcoR124I Journal of Molecular\u00a0Modeling 20 (7): \u00a02334.<\/li>\n<\/ol>\n