{"id":1029,"date":"2019-03-25T04:25:06","date_gmt":"2019-03-25T01:25:06","guid":{"rendered":"http:\/\/blog.ulubat.org\/?p=1029"},"modified":"2019-03-25T04:25:07","modified_gmt":"2019-03-25T01:25:07","slug":"dnayapisi-ve-daha-fazlasi","status":"publish","type":"post","link":"https:\/\/blog.ulubat.org\/index.php\/genel\/dnayapisi-ve-daha-fazlasi\/","title":{"rendered":"DNA, Yap\u0131s\u0131 ve Daha Fazlas\u0131"},"content":{"rendered":"\n

<\/p>\n\n\n\n

Nerdeyse hepimizin fikir sahibi\noldu\u011fu \u015feyler; DNA, Watson ve Crick, Rosalind Franklin, ikili sarmal yap\u0131 vb<\/p>\n\n\n\n

Peki ger\u00e7ekten DNA sarmal yap\u0131s\u0131 hakk\u0131nda\n1953 y\u0131l\u0131ndan beri bilinenler bu kadar m\u0131? <\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

DNA ve \u0130kili Sarmal Yap\u0131<\/strong><\/p>\n\n\n\n

1953 y\u0131l\u0131nda James Watson ve Francis Crick taraf\u0131ndan Nature <\/em>dergisinde yay\u0131nlanan makaleleri ile a\u00e7\u0131klad\u0131klar\u0131 DNA yap\u0131s\u0131, ikili sarmal yap\u0131 olmakla beraber bu iki yap\u0131n\u0131n hidrojen ba\u011flar\u0131 ile ba\u011fland\u0131klar\u0131n\u0131, i\u00e7erisinde bazlar sayesinde bu ba\u0131n ger\u00e7ekle\u015fti\u011fini ve adenin baz\u0131n\u0131n timin ile, guanin baz\u0131n\u0131n sitozin ile e\u015fle\u015ftiklerini belirtmi\u015flerdir. (1)<\/p>\n\n\n\n

Tabiki de bundan sonra\nara\u015ft\u0131rmalar devam etmi\u015f olup do\u011fada A-DNA, B-DNA ve Z-DNA olmak \u00fczere do\u011fada\n\u00fc\u00e7 konformasyonda bulundu\u011funu belirtmi\u015flerdir. Bu konformasyonlar i\u00e7inde Watson\nve Crick taraf\u0131ndan belirlenmi\u015f olan B konformasyonunun hakim oldu\u011fu g\u00f6r\u00fc\u015f\u00fc\nyayg\u0131nd\u0131r.<\/p>\n\n\n\n

Ancak dikkat edelimki B-DNA tek bir konformasyon ailesini de\u011fil, belli ko\u015fullarda g\u00f6zlenebilen konformasyon ailesi k\u00fcmelerini belirtmektedir.(2)<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Sadece iki sarmal olarak m\u0131 d\u00fc\u015f\u00fcn\u00fcld\u00fc? <\/strong><\/p>\n\n\n\n

                DNA\nyap\u0131s\u0131 hakk\u0131nda bir \u00e7ok teorinin at\u0131ld\u0131\u011f\u0131 d\u00f6nemlerde DNA yap\u0131s\u0131 hakk\u0131nda sorulan\nsorular\u0131n\u0131n \u00e7o\u011funun cevab\u0131n\u0131 kar\u015f\u0131layan Watson ve Crick\u2019in modeli tutulmu\u015f olup\ng\u00fcn\u00fcm\u00fcze kadar do\u011frulu\u011funu korumaktad\u0131r.<\/p>\n\n\n\n

                Bu d\u00f6nemde\n\u00fc\u00e7l\u00fc sarmal yap\u0131 gibi fikirler de ortaya at\u0131lsa da DNA sa\u011flaml\u0131\u011f\u0131 hakk\u0131nda\nak\u0131llardaki sorular\u0131n baz\u0131lar\u0131na yan\u0131t al\u0131namad\u0131\u011f\u0131 i\u00e7in Watson ve Crick modeli\ntercih edilmi\u015ftir.<\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

\u00dc\u00e7l\u00fc Sarmal DNA yap\u0131lar\u0131<\/em><\/strong><\/p>\n\n\n\n

Ben bu konu hakk\u0131nda yay\u0131mlanm\u0131\u015f eski\nmakale olarak Biochimica et Biophysica\nActa<\/em> adl\u0131 derginin 1957 y\u0131l\u0131ndaki Gary Felsenfeld ve Alexander Rich\u2019e ait\nmakaleye ula\u015fm\u0131\u015f bulunmaktay\u0131m.<\/p>\n\n\n\n

Garry Felsenfed ve Alexander Rich\u2019e\nait makalelerin yan\u0131 s\u0131ra yap\u0131y\u0131 anlamama yard\u0131mc\u0131 olan en anla\u015f\u0131labilir\nbilgiye Annual Review of Biochemistry dergisindeki 1995 y\u0131l\u0131nda Maxim D.\nFrank-Kamenetskii ve Sergei M. Mirkin taraf\u0131ndan yay\u0131mlanan makalesinde\ng\u00f6rmekteyim. (4) <\/p>\n\n\n\n

B-bi\u00e7imli DNA\u2019ya ba\u015fka bir\nipli\u011fin daha ba\u011flanmas\u0131 ile olu\u015fabilece\u011fini iddia eden bu DNA yap\u0131s\u0131n\u0131 daha\nayr\u0131nt\u0131l\u0131 incelemek i\u00e7in kaynak\u00e7a ve ileri okumaya koydu\u011fum makalelere\nsitelerden ve doi numaralar\u0131ndan ula\u015fabilirsiniz.<\/p>\n\n\n\n

DNA\u2019n\u0131n \u00fc\u00e7l\u00fc yap\u0131da laboratuvar ortam\u0131nda \u00fcretilebilmesi ad\u0131na biyoteknolojik y\u00f6ntemler kullan\u0131lsa da herhangi bir canl\u0131da bulundu\u011funa dair bilgiye ula\u015famasam da 2009 y\u0131l\u0131nda do\u011fan ve t\u0131p d\u00fcnyas\u0131nda haberlere konu olan Alfie Clamp\u2019\u0131n 7. Kromozomundaki bir ipli\u011findeki mutasyon sonucunda 3 sarmall\u0131 bir DNA\u2019ya sahip oldu\u011funu g\u00f6steren bir habere rastlad\u0131m. Bu olay\u0131n Alfie\u2019de birden \u00e7ok rahats\u0131zl\u0131\u011fa sebebiyet verdi\u011fi d\u00fc\u015f\u00fcn\u00fclse de nas\u0131l bir \u015fekilde etki etti\u011fi bulunamam\u0131\u015ft\u0131r. Bu bilgiyi olgu sunumu \u015feklinde makale arama motorlar\u0131ndan \u00e7e\u015fitli \u015fekillerde ula\u015fmaya \u00e7al\u0131\u015fsam da yay\u0131nlanm\u0131\u015f akademik \u00e7al\u0131\u015fmas\u0131na eri\u015femedim. Ancak okudu\u011fum haber sitesini kaynak\u00e7a ve ileri okumalara buraya b\u0131rak\u0131yorum J (5)<\/p>\n\n\n\n

D\u00f6rtl\u00fc Sarmal DNA yap\u0131lar\u0131<\/em><\/strong><\/p>\n\n\n\n

                G-quadruplex\nolarak da adland\u0131r\u0131lan bu yap\u0131lar n\u00fckleik asit olarak guaninin zengin oldu\u011fu dizilerde\nbulunmaktad\u0131r. Genellikle bu yap\u0131lar telomerik b\u00f6lgelerde, multiple genlerin\ntranskripsiyon d\u00fczenleyici b\u00f6lgelerinde ve onkogenlerde bulunmaktad\u0131r.  (6)<\/p>\n\n\n\n

                G-quadruplex\nyap\u0131lar\u0131n\u0131n telomerler u\u00e7lar\u0131n\u0131 koruyan ve telomer uzunlu\u011funu d\u00fczenleyen\nyap\u0131lar oldu\u011fu d\u00fc\u015f\u00fcn\u00fclmektedir.(7)<\/p>\n\n\n\n

\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Bu nedenle bu yap\u0131lar\u0131n \u00e7\u00f6z\u00fclmesi ve i\u015flevinin tam olarak anla\u015f\u0131lmas\u0131 kanser tedavisinde etkin rol oynayacakt\u0131r.<\/p>\n\n\n\n

Kaynak\u00e7a ve ileri okumalar<\/strong><\/p>\n\n\n\n

1-https:\/\/www.nature.com\/articles\/171737a0<\/a><\/p>\n\n\n\n

\nhttps:\/\/doi.org\/10.1038\/171737a0\n<\/div><\/figure>\n\n\n\n

2- https:\/\/www.sciencedirect.com\/science\/article\/pii\/0022283680901242?via%3Dihub<\/a><\/p>\n\n\n\n

\nhttps:\/\/doi.org\/10.1016\/0022-2836(80)90124-2\n<\/div><\/figure>\n\n\n\n

3-https:\/\/www.sciencedirect.com\/science\/article\/pii\/0006300257900914<\/p>\n\n\n\n

\nhttps:\/\/doi.org\/10.1016\/0006-3002(57)90091-4\n<\/div><\/figure>\n\n\n\n

4-https:\/\/www.annualreviews.org\/doi\/10.1146\/annurev.bi.64.070195.000433<\/p>\n\n\n\n

\nhttps:\/\/doi.org\/10.1146\/annurev.bi.64.070195.000433\n<\/div><\/figure>\n\n\n\n

5- https:\/\/www.dailymail.co.uk\/health\/article-1375697\/Alfie-Clamp-2-1st-person-born-extra-strand-DNA.html<\/p>\n\n\n\n

6- https:\/\/www.sciencedirect.com\/science\/article\/pii\/S0165614700014577?via%3Dihub<\/p>\n\n\n\n

\nhttps:\/\/doi.org\/10.1016\/S0165-6147(00)01457-7\n<\/div><\/figure>\n","protected":false},"excerpt":{"rendered":"

Nerdeyse hepimizin fikir sahibi oldu\u011fu \u015feyler; DNA, Watson ve Crick, Rosalind Franklin, ikili sarmal yap\u0131 vb Peki ger\u00e7ekten DNA sarmal<\/p>\n","protected":false},"author":54,"featured_media":1042,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1,7,19,6],"tags":[],"acf":[],"views":1683,"_links":{"self":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts\/1029"}],"collection":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/users\/54"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/comments?post=1029"}],"version-history":[{"count":6,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts\/1029\/revisions"}],"predecessor-version":[{"id":1041,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts\/1029\/revisions\/1041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/media\/1042"}],"wp:attachment":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/media?parent=1029"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/categories?post=1029"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/tags?post=1029"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}