Wyniki wyszukiwania - Biblioteka Nauki

1

The genetic code - 40 years on

100%

Szymański M. , Barciszewski J.

Acta Biochimica Polonica

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2007

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tom 54

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nr 1

51-54

EN

The genetic code discovered 40 years ago, consists of 64 triplets (codons) of nucleotides. The genetic code is almost universal. The same codons are assigned to the same amino acids and to the same START and STOP signals in the vast majority of genes in animals, plants, and microorganisms. Each codon encodes for one of the 20 amino acids used in the synthesis of proteins. That produces some redundancy in the code and most of the amino acids being encoded by more than one codon. The two cases have been found where selenocysteine or pyrrolysine, that are not one of the standard 20 is inserted by a tRNA into the growing polypeptide.

2

The new aspects of aminoacyl-tRNA synthetases.

100%

Szymański M. , Deniziak M. , Barciszewski J.

Acta Biochimica Polonica

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2000

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tom 47

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nr 3

821-834

EN

Aminoacyl-tRNA synthetases (AARS) are essential proteins found in all living organisms. They form a diverse group of enzymes that ensure the fidelity of transfer of genetic information from the DNA into the protein. AARS catalyse the attachment of amino acids to transfer RNAs and thereby establish the rules of the genetic code by virtue of matching the nucleotide triplet of the anticodon with its cognate amino acid. Here we summarise the effects of recent studies on this interesting family of multifunctional enzymes.

3

Ex-translational function of tRNAs and their fragments in cancer

100%

Mleczko A. , Celichowski P. , Bąkowska-Żywicka K.

Acta Biochimica Polonica

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2014

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tom 61

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nr 2

211-216

EN

Transfer RNA (tRNA) molecules are most commonly known as the molecular amino acids carriers and also because of the role they play in a protein biosynthesis process. However, tRNA biology has revealed stupendous levels of many unexpected discoveries that put a new light on tRNA function in different processes besides translation, like apoptosis or cancer development. In recent years various species of RNAs have been found differentially expressed in different types of cancer. In this review we focus our attention on tRNAs as well as on tRNA-derived small RNAs ex-translational functions in human cells in oncogenesis and oncobiology.

4

Genomics and the evolution of aminoacyl-tRNA synthesis.

88%

Ruan B. , Ahel I. , Ambrogelly A. , Becker H. D. , Bunjun S. , Feng L. , Tumbula-Hansen D. , Ibba M. , Korencic D. , Kobayashi H. , Jacquin-Becker C. , Mejlhede N. , Min B. , Raczniak G. , Rinehart J. , Stathopoulos C. , Li T. , Söll D.

Acta Biochimica Polonica

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2001

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tom 48

|

nr 2

313-321

EN

Translation is the process by which ribosomes direct protein synthesis using the genetic information contained in messenger RNA (mRNA). Transfer RNAs (tRNAs) are charged with an amino acid and brought to the ribosome, where they are paired with the corresponding trinucleotide codon in mRNA. The amino acid is attached to the nascent polypeptide and the ribosome moves on to the next codon. Thus, the sequential pairing of codons in mRNA with tRNA anticodons determines the order of amino acids in a protein. It is therefore imperative for accurate translation that tRNAs are only coupled to amino acids corresponding to the RNA anticodon. This is mostly, but not exclusively, achieved by the direct attachment of the appropriate amino acid to the 3'-end of the corresponding tRNA by the aminoacyl-tRNA synthetases. To ensure the accurate translation of genetic information, the aminoacyl-tRNA synthetases must display an extremely high level of substrate specificity. Despite this highly conserved function, recent studies arising from the analysis of whole genomes have shown a significant degree of evolutionary diversity in aminoacyl-tRNA synthesis. For example, non-canonical routes have been identified for the synthesis of Asn-tRNA, Cys-tRNA, Gln-tRNA and Lys-tRNA. Characterization of non-canonical aminoacyl-tRNA synthesis has revealed an unexpected level of evolutionary divergence and has also provided new insights into the possible precursors of contemporary aminoacyl-tRNA synthetases.

5

Nowo poznane funkcje transferowych kwasow rybonukleinowych i mozliwosci ich wykorzystania w biotechnologii

88%

Barciszewska M. Z. , Barciszewski J.

Biotechnologia

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1992

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nr 1

63-75

6

Editing of plant mitochondrial transfer RNAs

88%

Fey J. , Weil J. H. , Tomita K. , Cosset A. , Dietrich A. , Small I. , Maréchal-Drouard L.

Acta Biochimica Polonica

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2001

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tom 48

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nr 2

383-389

EN

Editing in plant mitochondria consists in C to U changes and mainly affects messenger RNAs, thus providing the correct genetic information for the biosynthesis of mitochondrial (mt) proteins. But editing can also affect some of the plant mt tRNAs encoded by the mt genome. In dicots, a C to U editing event corrects a C:A mismatch into a U:A base-pair in the acceptor stem of mt tRNAPhe (GAA). In larch mitochondria, three C to U editing events restore U:A base-pairs in the acceptor stem, D stem and anticodon stem, respectively, of mt tRNAHis (GUG). For both these mt tRNAs editing of the precursors is a prerequisite for their processing into mature tRNAs. In potato mt tRNACys (GCA), editing converts a C28:U42 mismatch in the anticodon stem into a U28:U42 non-canonical base-pair, and reverse transcriptase minisequencing has shown that the mature mt tRNACys is fully edited. In the bryophyte Marchantia polymorpha this U residue is encoded in the mt genome and evolutionary studies suggest that restoration of the U28 residue is necessary when it is not encoded in the gene. However, in vitro studies have shown that neither processing of the precursor nor aminoacylation of tRNACys requires C to U editing at this position. But sequencing of the purified mt tRNACys has shown that is present at position 28, indicating that C to U editing is a prerequisite for the subsequent isomerization of U into Ψ at position 28.

7

Mini-tRNA jako narzedzie identyfikacji elementow struktury tRNA opowiedzialnych za aminoacylacje

75%

Bakowska K. , Dudzinska-Bajorek B. , Twardowski T.

Postępy Biochemii

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2004

|

tom 50

|

nr 1

2-10

8

Selective binding of amino acids to yeast tRNA under high ionic strength conditions

75%

Stroinski A. , Kedzierski W.

Roczniki Akademii Rolniczej w Poznaniu. Ogrodnictwo

|

1994

|

tom 22

71-77

9

Redagowanie transferowych RNA organelli

63%

Rurek M.

Postępy Biologii Komórki

|

1994

|

tom 21

|

nr 4

391-394

10

Wplyw olowiu na niektore elementy biosyntezy bialka

51%

Pasternak K.

Zeszyty Naukowe. Polska Akademia Nauk. Komitet Naukowy przy Prezydium PAN Człowiek i Środowisko

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1998

|

tom 21

307-312

11

Struktura rybosomu prokariotycznego.

51%

Dudzinska B. , Twardowski T.

Postępy Biochemii

|

2001

|

tom 47

|

nr 1

19-29

12

Bialka jedwabiu B.mori - charakterystyka, biosynteza i regulacja ekspresji genow

44%

Kludkiewicz B. , Grzelak K.

|

tom 39

|

nr 2

105-111