{"id":128886,"date":"2024-11-22T18:41:01","date_gmt":"2024-11-22T11:41:01","guid":{"rendered":"https:\/\/hotvideos24.online\/?p=128886"},"modified":"2024-11-22T18:41:01","modified_gmt":"2024-11-22T11:41:01","slug":"origin-of-life-research-finds-rna-can-favor-both-left-and-right-handed-proteins","status":"publish","type":"post","link":"https:\/\/hotvideos24.online\/?p=128886","title":{"rendered":"Origin of life research finds RNA can favor both left- and right-handed proteins"},"content":{"rendered":"<p> <script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-3711241968723425\"\r\n     crossorigin=\"anonymous\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-layout-key=\"-fb+5w+4e-db+86\"\r\n     data-ad-client=\"ca-pub-3711241968723425\"\r\n     data-ad-slot=\"7910942971\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><br \/>\n<\/p>\n<div>\n<div class=\"article-gallery lightGallery\">\n<div data-thumb=\"https:\/\/scx1.b-cdn.net\/csz\/news\/tmb\/2024\/nasa-mystery-of-lifes.jpg\" data-src=\"https:\/\/scx2.b-cdn.net\/gfx\/news\/hires\/2024\/nasa-mystery-of-lifes.jpg\" data-sub-html=\"A diagram of left-handed and right-handed versions of the amino acid isovaline, found in the Murchison meteorite. Credit: NASA\">\n<figure class=\"article-img\">\n            <img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/scx1.b-cdn.net\/csz\/news\/800a\/2024\/nasa-mystery-of-lifes.jpg\" alt=\"NASA: Mystery of life's handedness deepens\" title=\"A diagram of left-handed and right-handed versions of the amino acid isovaline, found in the Murchison meteorite. Credit: NASA\" width=\"800\" height=\"529\"\/><figcaption class=\"text-darken text-low-up text-truncate-js text-truncate mt-3\">\n                A diagram of left-handed and right-handed versions of the amino acid isovaline, found in the Murchison meteorite. Credit: NASA<br \/>\n            <\/figcaption><\/figure>\n<\/p><\/div>\n<\/div>\n<p>The mystery of why life uses molecules with specific orientations has deepened with a discovery that RNA\u2014a key molecule thought to have potentially held the instructions for life before DNA emerged\u2014can favor making the building blocks of proteins in either the left-hand or the right-hand orientation. Resolving this mystery could provide clues to the origin of life. The findings <a href=\"https:\/\/www.nature.com\/articles\/s41467-024-52362-x\" target=\"_blank\" rel=\"noopener\">appear<\/a> in research recently published in <i>Nature Communications<\/i>.<\/p>\n<p>Proteins are the workhorse molecules of life, used in everything from structures like hair to enzymes (catalysts that speed up or regulate <a href=\"https:\/\/phys.org\/tags\/chemical+reactions\/\" rel=\"tag\" class=\"textTag\">chemical reactions<\/a>). Just as the 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acid building blocks in a huge variety of arrangements to make millions of different proteins.<\/p>\n<p>Some <a href=\"https:\/\/phys.org\/tags\/amino+acid+molecules\/\" rel=\"tag\" class=\"textTag\">amino acid molecules<\/a> can be built in two ways, such that mirror-image versions exist, like your hands, and life uses the left-handed variety of these amino acids. Although life based on right-handed amino acids would presumably work fine, the two mirror images are rarely mixed in biology, a characteristic of life called homochirality. It is a mystery to scientists why life chose the left-handed variety over the right-handed one.<\/p>\n<p>DNA (deoxyribonucleic acid) is the molecule that holds the instructions for building and running a living organism. However, DNA is complex and specialized; it &#8220;subcontracts&#8221; the work of reading the instructions to RNA (ribonucleic acid) molecules and building proteins to ribosome molecules.<\/p>\n<p>DNA&#8217;s specialization and complexity lead scientists to think that something simpler should have preceded it billions of years ago during the early evolution of life. A leading candidate for this is RNA, which can both store genetic information and build proteins. The hypothesis that RNA may have preceded DNA is called the &#8220;RNA world&#8221; hypothesis.<\/p>\n<p>If the RNA world proposition is correct, then perhaps something about RNA caused it to favor building left-handed proteins over right-handed ones. However, the new work did not support this idea, deepening the mystery of why life went with left-handed proteins.<\/p>\n<p>The experiment tested RNA molecules that act like enzymes to build proteins, called ribozymes. &#8220;The experiment demonstrated that ribozymes can favor either left- or right-handed amino acids, indicating that RNA worlds, in general, would not necessarily have a strong bias for the form of amino acids we observe in biology now,&#8221; said Irene Chen, of the University of California, Los Angeles (UCLA) Samueli School of Engineering, corresponding author of the paper.<\/p>\n<p>In the experiment, the researchers simulated what could have been early-Earth conditions of the RNA world. They incubated a solution containing ribozymes and amino acid precursors to see the relative percentages of the right-handed and left-handed amino acid, phenylalanine, that it would help produce.<\/p>\n<p>They tested 15 different ribozyme combinations and found that ribozymes can favor either left-handed or right-handed amino acids. This suggested that RNA did not initially have a predisposed chemical bias for one form of amino acids. This lack of preference challenges the notion that early life was predisposed to select left-handed-amino acids, which dominate in modern proteins.<\/p>\n<p>&#8220;The findings suggest that life&#8217;s eventual homochirality might not be a result of chemical determinism but could have emerged through later evolutionary pressures,&#8221; said co-author Alberto V\u00e1zquez-Salazar, a UCLA postdoctoral scholar and member of Chen&#8217;s research group.<\/p>\n<div class=\"w-100 my-4 article-main__more bg-light p-3 border\">\n<p class=\"mb-3\">\n        Discover the latest in science, tech, and space with over <strong>100,000 subscribers<\/strong> who rely on Phys.org for daily insights.<br \/>\n        Sign up for our <a href=\"https:\/\/sciencex.com\/help\/newsletter\/\" target=\"_blank\" rel=\"noopener\">free newsletter<\/a> and get updates on breakthroughs,<br \/>\n        innovations, and research that matter\u2014<strong>daily or weekly<\/strong>.\n    <\/p>\n<\/div>\n<p>Earth&#8217;s prebiotic history lies beyond the oldest part of the fossil record, which has been erased by plate tectonics, the slow churning of Earth&#8217;s crust. During that time, the planet was likely bombarded by asteroids, which may have delivered some of life&#8217;s building blocks, such as amino acids. In parallel to chemical experiments, other <a href=\"https:\/\/phys.org\/tags\/origin+of+life\/\" rel=\"tag\" class=\"textTag\">origin-of-life<\/a> researchers have been looking at molecular evidence from meteorites and asteroids.<\/p>\n<p>&#8220;Understanding the chemical properties of life helps us know what to look for in our search for life across the solar system,&#8221; said co-author Jason Dworkin, senior scientist for astrobiology at NASA&#8217;s Goddard Space Flight Center in Greenbelt, Maryland, and director of Goddard&#8217;s Astrobiology Analytical Laboratory.<\/p>\n<p>Dworkin is the project scientist on NASA&#8217;s OSIRIS-REx mission, which extracted samples from the asteroid Bennu and delivered them to Earth last year for further study.<\/p>\n<p>&#8220;We are analyzing OSIRIS-REx <a href=\"https:\/\/curator.jsc.nasa.gov\/osirisrex\/index.cfm\" target=\"_blank\" rel=\"noopener\">samples<\/a> for the chirality (handedness) of individual amino acids, and in the future, <a href=\"https:\/\/science.nasa.gov\/mission\/mars-sample-return\/\" target=\"_blank\" rel=\"noopener\">samples from Mars<\/a> will also be tested in laboratories for evidence of life including ribozymes and proteins,&#8221; said Dworkin.<\/p>\n<div class=\"article-main__more p-4\">\n<p><strong>More information:<\/strong><br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tJosh Kenchel et al, Prebiotic chiral transfer from self-aminoacylating ribozymes may favor either handedness, <i>Nature Communications<\/i> (2024). <a data-doi=\"1\" href=\"https:\/\/dx.doi.org\/10.1038\/s41467-024-52362-x\" target=\"_blank\" rel=\"noopener\">DOI: 10.1038\/s41467-024-52362-x<\/a><\/p>\n<\/p><\/div>\n<div class=\"d-inline-block text-medium mt-4\">\n<p>\n\t\t\t\t\t\t\t\t\t\t\t\t\tProvided by<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/phys.org\/partners\/nasa-s-goddard-space-flight-center\/\">NASA&#8217;s Goddard Space Flight Center<\/a><br \/>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a class=\"icon_open\" href=\"http:\/\/www.nasa.gov\/centers\/goddard\/home\/index.html\" target=\"_blank\" rel=\"nofollow noopener\"><br \/>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<svg>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<use href=\"https:\/\/phys.b-cdn.net\/tmpl\/v6\/img\/svg\/sprite.svg#icon_open\" x=\"0\" y=\"0\"\/>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/svg><br \/>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/p>\n<\/p><\/div>\n<p>\t\t\t\t\t\t\t\t\t\t<!-- print only --><\/p>\n<div class=\"d-none d-print-block\">\n<p>\n\t\t\t\t\t\t\t\t\t\t\t\t<strong>Citation<\/strong>:<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tOrigin of life research finds RNA can favor both left- and right-handed proteins (2024, November 21)<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tretrieved 22 November 2024<br \/>\n\t\t\t\t\t\t\t\t\t\t\t\tfrom https:\/\/phys.org\/news\/2024-11-life-rna-favor-left-proteins.html\n\t\t\t\t\t\t\t\t\t\t\t <\/p>\n<p>\n\t\t\t\t\t\t\t\t\t\t\t This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no<br \/>\n\t\t\t\t\t\t\t\t\t\t\t part may be reproduced without the written permission. The content is provided for information purposes only.\n\t\t\t\t\t\t\t\t\t\t\t <\/p>\n<\/p><\/div>\n<\/p><\/div>\n<p><script id=\"facebook-jssdk\" async=\"\" src=\"https:\/\/connect.facebook.net\/en_US\/sdk.js\"><\/script><br \/>\n<br \/><script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js?client=ca-pub-3711241968723425\"\r\n     crossorigin=\"anonymous\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-layout-key=\"-fb+5w+4e-db+86\"\r\n     data-ad-client=\"ca-pub-3711241968723425\"\r\n     data-ad-slot=\"7910942971\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><br \/>\n<br \/><div data-type=\"_mgwidget\" data-widget-id=\"1660802\">\r\n<\/div>\r\n<script>(function(w,q){w[q]=w[q]||[];w[q].push([\"_mgc.load\"])})(window,\"_mgq\");\r\n<\/script>\r\n<br \/>\n<br \/><a href=\"https:\/\/phys.org\/news\/2024-11-life-rna-favor-left-proteins.html\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A diagram of left-handed and right-handed versions of the amino acid isovaline, found in the Murchison meteorite. Credit: NASA The mystery of why life uses molecules with specific orientations has &hellip; <a href=\"https:\/\/hotvideos24.online\/?p=128886\" class=\"more-link\">Read More<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8628],"tags":[],"class_list":["post-128886","post","type-post","status-publish","format-standard","hentry","category-science","entry"],"_links":{"self":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts\/128886","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=128886"}],"version-history":[{"count":0,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=\/wp\/v2\/posts\/128886\/revisions"}],"wp:attachment":[{"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=128886"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=128886"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hotvideos24.online\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=128886"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}