Download presentation
Presentation is loading. Please wait.
Published byValentina Boyt Modified over 9 years ago
1
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -1- Ivo Kabelka, 1 Jakub Štěpán, 1,2 Jaroslav Koča 1,2, and Petr Kulhánek 1,2 kulhanek@chemi.muni.cz 1 National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic 2 CEITEC – Central European Institute of Technology, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic Study of BsoBI Endonuclease By Molecular Dynamics
2
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -2- BsoBI Nuclease type II restriction endonuclease from Geobacillus stearothermophilus optimal cleavage at 65 ˚C recognizes short palindromatic sequence C|PyCGPuG cofactor - 2 Mg 2+ atoms Ruan, H.; Lunnen, K. D.; Scott, M. E.; Moran, L. S.; Slatko, B. E.; Pelletier, J. J.; Hess, E. J.; Benner, J., 2nd; Wilson, G. G.; Xu, S. Y. Cloning and sequence comparison of AvaI and BsoBI restriction-modification systems. Mol. Gen. Genet. 1996, 252, 695–699. homodimeric enzyme - both in free form and in complex with DNA (2x323 AA) capable of cleaving both linear and circular DNA molecules 20 Å long tunnel for DNA recognition complete encirclement of DNA helical domains catalytic domains monomer A monomer B DNA
3
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -3- Experimental study Dikić, J. The conformational dynamics of BsoBI, analyzed by fluorescence spectroscopy down to the single molecule level. Thesis, University of Justus Liebig, Giessen, 2009. fluorescent probes: acceptor and donor FRET – Fluorescence Resonance Energy Transfer efficiency is proportional to acceptor-donor distance single molecule level (diluted solution) Proposed conformational changes
4
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -4- Motivation find structure of "opened" state(s) find pathways how DNA enters to the active site confirm FRET experiments find structure of pre-reaction complex
5
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -5- Molecular Dynamics - complex input structure PDB ID: 1DC1 pmemd from AMBER v12 parm99SBbsc0 + TIP3P water c(NaCl) ~ 0.15 M 298 K and 1 bar apo-enzyme (no ion cofactors) CPU/GPU protein + DNA
6
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -6- Molecular Dynamics – no DNA only protein DNA removed with DNA (150 ns) no DNA
7
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -7- Molecular Dynamics – no DNA only protein DNA removed d1
8
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -8- Metadynamics history dependent biasing potential converge to the free energy reaction (collective) variables 1 CV – distance between catalytic domains pmemd v10/PMFLib v4.0 h=0.1 kcal/mol =0.5 Å t s =2 ps CPU only Laio, A.; Parrinello, M. P. Natl. Acad. Sci. USA 2002, 99, 12562–12566.
9
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -9- MTD - Collective Variable Evolutions
10
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -10- MTD - Free Energy Estimates
11
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -11- Principal Component Analysis no DNA MTD Index EigenValue Å2Å2 15390.5 2599.9 3353.7 4177.0 5123.1 682.1 771.3 843.3 929.3 1027.7 Fluctuation matrix Diagonalization Projectionsmode #1mode #2
12
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -12- PCA Projections 0 ns (start) 16 ns (end) no DNA MTD
13
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -13- Opened Enzyme Average distance 16 Å closed with DNA 7Å
14
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -14- Contradictions Dikić, J. The conformational dynamics of BsoBI, analyzed by fluorescence spectroscopy down to the single molecule level. Thesis, University of Justus Liebig, Giessen, 2009. In the apo-enzyme (no cofactor present) both distances are shorter than in the complex.
15
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -15- Contradictions Dikić, J. The conformational dynamics of BsoBI, analyzed by fluorescence spectroscopy down to the single molecule level. Thesis, Giessen, 2009. In the apo-enzyme (no cofactor present) both distances are shorter than in the complex. MD simulations
16
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -16- Donor/Acceptor Structures Alexa594 CC 19 Å
17
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -17- Donor/Acceptor Dynamics E153C E290C "closed""open" protein restrained implicit solvent 600 K
18
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -18- Conclusions Main outcomes
19
MIB VI, 16 th – 19 th September 2013, Mariánské lázně -19- Acknowledgements Financial support CEITEC GACR Computational resources MetaCentrum CERIT-SC
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.