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- Published: Friday, 26 February 2016 12:26
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Our group is involved in theoretical and experimental research on nucleic acids and proteins. The current focus is on RNA sequence-structure-function relationships (in particular 3D modeling), RNA-protein complexes, and enzymes acting on RNA.
We study the rules that govern the sequence-structure-function relationships in proteins and nucleic acids and use the acquired knowledge to predict structures and functions for uncharacterized gene products, to alter the known structures and functions of proteins and RNAs and to engineer molecules with new properties.
Our key strength is in the integration of various types of theoretical and experimental analyses. We develop and use computer programs for modeling of protein three-dimensional structures based on heterogenous, low-resolution, noisy and ambivalent experimental data. We are also involved in genome-scale phylogenetic analyses, with the focus on identification of proteins that belong to particular families. Subsequently, we characterize experimentally the function of the most interesting new genes/proteins identified by bioinformatics. We also use theoretical predictions to guide protein engineering, using rational and random approaches. Our ultimate goal is to identify complete sets of enzymes involved in particular metabolic pathways (e.g. RNA modification, DNA repair) and to design proteins with new properties, in particular enzymes with new useful functions, which have not been observed in the nature.
We are well-equipped with respect to both theoretical and experimental analyses. Our lab offers excellent environment for training of young researchers in both bioinformatics and molecular biology/biochemistry of protein-nucleic acid interactions.
More Good Science
RNA Masonry is a computer program that builds atomic models of RNA molecules using recurrent 3D motifs available in RNA Bricks database (http://iimcb.genesilico.pl/rnabricks). The program exploits hierarchical organization of RNA structures, which are composed of regularly shaped double-stranded helices, and irregularly shaped loop motifs. Algorithms implemented in RNA Masonry merge these motifs to build a model that have the user-provided secondary structure, and
plausible local geometry. The program can also use additional restraints like tertiary contacts or small angle scattering data. Here you can download standalone version of the program. Currently only Linux and Mac OSX operating systems are supported.
$ tar -zxvf
rnamasonry_09
.tgz
$ cd rnamasonry_09
$ ./rnamasonry.sh
$ ./rnamasonry.sh --sync
$ cat examples/tRNA.txt
> 1ehz The crystal structure of yeast phenylalanine tRNA at 1.93 A resolution
GCGGAUUUAgCUCAGuuGGGAGAGCgCCAGAcUgAAgAucUGGAGgUCcUGUGuuCGaUCCACAGAAUUCGCACCA
(((((((...(((........)))..(((...........)))......((((.......)))).)))))))....
$ ./rnamasonry.sh
Usage: rnamasonry.py [options]
Options:
-h, --help show this help message and exit
-i FILENAME, --input_file=FILENAME
Input file containing RNA sequence and secondary
structure or a PDB/mmCIF file. Examples:
examples/tRNA.txt,1EHZ.pdb,1EHZ.cif
-n 4, --n_threads=4 Number of threads [default: 4]
--local_db=PATH Path to the fragment database directory [default:
/Users/gchojnowski/xprojects/rnamasonry/local_db]
--refine Perform a simple simulated annealing refinement only
[default: replica exchange]
--sync Sync local list of RNA fragments with RNA Bricks2
database (updated once a week)
--steps=1000 Number of MCMC refinement or replica exchange steps
[default: 1000]
-f, --fast Use no more that 10 frags for each node [default:
100]. For testing purposes only.
--freeze=SELECTION Keep all fragment with selected nucleotides frozen
[e.g. --freeze=12:25,30:39]
--start-model=FILENAME
Path to a json file with dictionary defining starting
nodes configuration [default: none]
--save-decoys=FLOAT Save given fraction of lowest-energy replica exchange
decoys in PDB format [default: 0.0]
--rg=FLOAT Target structure radius of gyration [default: none]
--reference-model=FILENAME
Reference model to calculate plot of rmsd vs energy.
--saxs-data=FILENAME Experimental SAXS curve for scoring tentative models.
This option requires CRYSOL v2.8.3
--crysol Use CRYSOL instead of a local FOXS copy (not available
on Mac)NOTE: you must provide CRYSOL by yourself
$ ./rnamasonry.sh -i examples/tRNA.txt
this will start a replica exchange Monte-Carlo model-building simulation for the example secondary structure. After roughly 30 minutes a final model will be saved in a file "rms_tRNA_txt_1/clust_00001.pdb"
Selected awards of current and former group members
START Fellowships (Foundation for Polish Science):
Fellowship for Ph.D. Students (Marshall of the Masovia Province):
Fellowships for Outstanding Young Scientists (Polish Ministry of Science):
Award of the Polish Biochemical Society and Sigma-Aldrich (the best PhD thesis in the field of biochemistry):
Parnas Award of the Polish Biochemical Society – 1 awardee per year (for the best publication in biochemistry) for the publication: "Structural analysis of human 2′-O-ribose methyltransferases involved in mRNA cap structure formation". Nature Commun., 2014, 5:3004, doi:10.1038/ncomms4004, *Smietanski M*, *Werner M*, *Purta E*, *Kaminska KH*, Stepinski J, Darzynkiewicz E, Nowotny M, *Bujnicki JM*
Breakthrough Article status for the publication: "Sequence-specific cleavage of dsRNA by Mini-III RNase" Nucleic Acids Res., 2015, 43(5):2864-73., *Glow D*, *Pianka D*, *Sulej A*, *Kozlowski L*, *Czarnecka J*, *Chojnowski G*, *Skowronek KJ*, *Bujnicki JM*
We developed a new program for RNA folding simulations and 3D structure prediction. SimRNA can fold RNA molecules using only sequence information, and it can use additional restraints. It has been validated in RNA Puzzles. Research published in Nucleic Acids Research, December 19, 2015, doi: 10.1093/nar/gkv1479..