Kislotai ribonukleinat – KRN.

Kislotai ribonukleinat monandi KDN polimer buda, monomerhoi on nukleotidhoyand. Asoshoi nitrogenii se nukleotid niz monandi nukleo tidhoi tarkibi KDN (adenin, guanin, sitozin) meboshand:

asosi nitrogenii chahorum dar KRN ba joi timin uratsil ishtirok menamoyad. Nukleotidhoi KRN az nukleotidhoi KDN bo sokhti angishtobhoi tarkibashon niz farq mekunand; onho dar khud pentozai digar – ba joi dezoksiriboza-riboza dorand. Dar zanjiri KRN nukleotidho bo rohi ba vujud omadani bandho bayni ribozai yak nukleotid va boqimondai kislotai fosfati nukleotidi digar payvast meshavand.

KRN akhborro oid ba paydarhamii aminokislotaho dar safedaho, yane oid ba strukturai safedaho, az khromosoma ba mavzei sintezi onho guzaronida, dar hosilshavii safedaho ishtirok menamoyad. Az rui struktura KRN-a dusilsi-

la (duzanjira) va yaksilsila (yakzanjira) meshavad. KRN-a dusilsila dar baze virusho hamchun nigohdorandai akhbori genetiki khizmat menamoyad (nigared ba bobi 5), yane dar onho funksiyai khromosomaro ijro menamoyad.

CHand navi KRN-a yaksilsila mavjudand. Onho az rui funksiya yo mavqei khud dar hujayra nom giriftaand. Qismi ziyodi sitoplazmaro (to 80-90%) KRN-i ribosomi (KRN-r), ki dar ribosomaho mavjud ast, tashkil menamoyad. Moleku-

lai KRN-r kalon nest va taqriban az 3-5 hazor nukleotidho iborat meboshad. Kislotahoi ribonukleinat az darozii  qismi kislotahoi dezoksiribonukleinat, ki dar hamon qism onho sintez meshavand, vobastagi dorand. Molekulai KRN-a metavonad az 3000–30000 nukleotidho iborat boshad.

KRN–i naqliyoti (KRN-n) 76–85 nukleotid- horo dokhil karda, yakchand funksiyaro ijro menamoyad (rasmi 3.10). On aminokislotahoro ba joi (nuqtai) sintezi safeda rasonda, mavqei aniqi aminokislotahoro dar ribosoma muayyan mekunad.