Equipe da Universidade do Colorado descobre uma minúscula molécula de RNA com grandes implicações para a origem da vida

segunda-feira, fevereiro 22, 2010

CU Team Discovers Tiny RNA Molecule With Big Implications for the Origin of Life

February 22, 2010

An extremely small RNA molecule created by a University of Colorado at Boulder team can catalyze a key reaction needed to synthesize proteins, the building blocks of life. The findings could be a substantial step toward understanding "the very origin of Earthly life," the lead researcher contends.

The smallest RNA enzyme ever known to perform a cellular chemical reaction is described in a paper published this week in the Proceedings of the National Academy of Sciences. The paper was written by CU graduate student Rebecca Turk, research associate Nataliya Chumachenko and Professor Michael Yarus of the molecular, cellular and developmental biology department.

Michael Yarus

Cellular RNA can have hundreds or thousands of its basic structural units, called nucleotides. Yarus' team focused on a ribozyme -- a form of RNA that can catalyze chemical reactions -- with only five nucleotides.

Tom Blumenthal, a professor and chair of the MCDB department, noted that Tom Cech, a Nobel laureate and distinguished professor of chemistry and biochemistry at CU, and Professor Norman Pace of MCDB, independently discovered that RNA can act as an enzyme, carrying out chemical reactions. That "pioneering work" has been carried on further by Yarus, Blumenthal said.

Read more here/Leia mais aqui: Colorado University at Boulder


Multiple translational products from a five-nucleotide ribozyme

Rebecca M. Turk a, Nataliya V. Chumachenko b, and Michael Yarus a,1

-Author Affiliations

aDepartment of Molecular, Cellular, and Developmental Biology, and

bCooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309-0347

Edited by Harry F. Noller, University of California Santa Cruz, Santa Cruz, CA, and approved January 27, 2010 (received for review November 14, 2009)


An indispensable step in protein biosynthesis is the 2′(3′) aminoacylation of tRNA by aminoacyl-tRNA synthetases. Here we show that a similar activity exists in a tiny, 5-nt-long RNA enzyme with a 3-nt active center. The small ribozyme initially trans-phenylalanylates a partially complementary 4-nt RNA selectively at its terminal 2′-ribose hydroxyl using PheAMP, the natural form for activated amino acid. The initial 2′ Phe-RNA product can be elaborated into multiple peptidyl-RNAs. Reactions do not require divalent cations, and have limited dependence on monovalent cations. Small size and minimal requirements for regiospecific translational activity strongly support the hypothesis that minuscule RNA enzymes participated in early forms of translation.

aminoacyl-RNA    enzyme    evolution   peptidyl-RNA   RNA


1To whom correspondence should be addressed. E-mail:yarus@stripe.colorado.edu.

Author contributions: R.M.T. and M.Y. designed research; R.M.T. performed research; N.V.C. contributed new reagents/analytic tools; M.Y. analyzed data; and R.M.T. and M.Y. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

This article contains supporting information online at www.pnas.org/cgi/content/full/0912895107/DCSupplemental.


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Origem da vida: só faltava esta minúscula molécula. Agora vai: Abracadabra, Alakazam, Presto!!!