A cikin shekaru goma da suka gabata, fasahar gyaran kwayoyin halittar da ta dogara da CRISPR ta bunkasa cikin sauri, kuma an yi nasarar amfani da ita wajen magance cututtukan kwayoyin cuta da kuma ciwon daji a gwajin asibiti na dan Adam.A lokaci guda kuma, masana kimiyya a duniya koyaushe suna matsa sabbin kayan aiki tare da yuwuwar gyara kwayoyin halitta don magance matsalolin kayan aikin gyaran kwayoyin halitta da yanke hukunci.

A cikin watan Satumba na 2021, ƙungiyar Zhang Feng ta buga takarda a cikin mujallar Kimiyya [1], kuma ta gano cewa ɗimbin fastoci masu lamba RNA suna jagorantar enzymes na acid nucleic kuma suna kiran shi tsarin Omega (ciki har da ISCB, ISRB, TNP8).Binciken ya kuma gano cewa tsarin Omega yana amfani da wani sashe na RNA don jagorantar yanke sarkar DNA guda biyu, wato ωRNA.Mafi mahimmanci, waɗannan enzymes nucleic acid suna da ƙananan ƙananan, kawai kusan 30% na CAS9, wanda ke nufin cewa za a iya ba da su zuwa sel.

A ranar 12 ga Oktoba, 2022, ƙungiyar Zhang Feng ta buga a cikin mujallar yanayi mai suna: Tsarin Omega Nickase ISRB a cikin Complex tare da ωrna da DNA Target [2].

Binciken ya ci gaba da nazarin tsarin microscope na lantarki daskararre na ISRB-ωRNA da hadadden DNA da aka yi niyya a cikin tsarin Omega.

ISCB shine kakan CAS9, kuma ISRB abu ɗaya ne na rashin HNH nucleic acid domain ISCB, don haka girman ya fi ƙanƙanta, kusan amino acid 350 kawai.DNA kuma yana ba da tushe don ƙarin haɓakawa da canjin injiniya.

IsrB mai jagorar RNA memba ne na dangin OMEGA wanda babban dangi IS200/IS605 na transposons ya yi.Daga nazarin phylogenetic da yanki na musamman da aka raba, IsrB mai yiwuwa ya zama farkon IscB, wanda shine kakan Cas9.

A cikin Mayu 2022, Laboratory Dragon na Jami'ar Cornell ya buga takarda a cikin mujallar Kimiyya [3], tana nazarin tsarin IscB-ωRNA da tsarin sa na yanke DNA.

Idan aka kwatanta da IscB da Cas9, IsrB ba shi da yankin HNH nuclease, REC lobe, da mafi yawan wuraren hulɗar tsarin PAM, don haka IsrB ya fi ƙasa da Cas9 (kimanin amino acid 350 kawai).Koyaya, ƙaramin girman IsrB yana daidaitawa ta babban jagorar RNA (Omega RNA ɗinta kusan 300 nt tsayi).

Tawagar Zhang Feng ta yi nazari kan tsarin microscope na cryo-electron na IsrB (DtIsrB) daga kwayoyin cutar anaerobic Desulfovirgula thermocuniculi da hadaddun ωRNA da DNA da aka yi niyya.Binciken tsari ya nuna cewa gaba ɗaya tsarin furotin na IsrB ya raba tsarin kashin baya tare da furotin Cas9.

Amma bambancin shine Cas9 yana amfani da lobe na REC don sauƙaƙe ƙaddamar da manufa, yayin da IsrB ya dogara da ωRNA, wani ɓangare na wanda ya samar da wani hadadden tsari mai girma uku wanda ke aiki kamar REC.

Don ƙarin fahimtar sauye-sauyen tsarin IsrB da Cas9 a lokacin juyin halitta daga RuvC, ƙungiyar Zhang Feng ta kwatanta maƙasudin tsarin dauri na DNA na RuvC (TtRuvC), IsrB, CjCas9 da SpCas9 daga Thermus thermophilus.

Binciken tsarin IsrB da ωRNA nasa yana fayyace yadda IsrB-ωRNA ya haɗu tare da gano DNA da ke da niyya, kuma yana ba da tushe don ƙarin haɓakawa da injiniyan wannan ƙaramin ƙwayar cuta.Kwatanta da sauran tsarin da RNA ke jagoranta yana nuna hulɗar aiki tsakanin sunadarai da RNA, haɓaka fahimtar ilimin halitta da juyin halittar waɗannan tsarin mabambanta.

Hanyoyin haɗi:

1.https://www.science.org/doi/10.1126/science.abj6856

2.https://www.science.org/doi/10.1126/science.abq7220

3.https://www.nature.com/articles/s41586-022-05324-6