Morekuru reDNA vari: kwevari STRUCTURAL sangano

Morekuru reDNA - a polynucleotide monomer dzakabatana idzo ina deoxyribonucleotide (dAMF, dGMP, dCMP uye dTMP). Nhamba kutevedzana pakati nucleotides izvi kupinda DNA ezvinhu zvipenyu zvakasiyana zvakasiyana. Kunze huru nitrogenous nezvigadziko mu DNA rinewo zvimwe zviduku zvigadziko deoxyribonucleotides pamwe 5-methylcytosine, 5-oksimetiltsitozin, 6-methylaminopurine.

Kamwe paiva nomukana kushandisa nzira X-ray crystallography kudzidza zvoutachiona macromolecules uye kuwana zvakakwana X-ray, zvakakwanisika azive samolecular maumbirwo DNA. Akati nzira inobva kuti danda kubva yakafanana maekisirei chiitiko pamusoro crystalline sumbu maatomu, anoumba rimwe diffraction muenzaniso, izvo kazhinji kunobva mabhomba kurema maatomu, uye avo nzvimbo muchadenga. Mune 40s remakore rapfuura, dzidziso-dimensional matatu nemamiriro morekuru reDNA raitwa mberi. U. Astbury akaratidza kuti deoxyribonucleic asidhi ndiwo murwi wemagazini seari sandara nucleotides.

The chikuru nemamiriro morekuru reDNA

Under chinonyanya mamiriro ose nucleic acids, chinorehwa kutevedzana kwezviitiko nucleotides vari polynucleotide urongwa DNA cheni. Nucleotides zvinesungano pamwe phosphodiester zvisungo zviri yakaumbwa pakati OH boka iri 5 nzvimbo imwe nucleotide uye deoxyribose kuti OH-boka munzvimbo 3 imwe pentose.

The zvoutachiona ehupfumi ari nucleic iine acid reshiyo pakutsvaga Qualitative uye akatevedza nucleotide kutevedzana yacho polynucleotide cheni.

The nucleotide Zvinoumba DNA kubva zvipenyu akasiyana taxonomic mapoka wakananga uye pakutsvaga reshiyo (G + C) / (A + T). Kushandisa chinhu specificity akanga pakutsvaga mwero heterogeneity pamusoro nucleotide Zvinoumba DNA kubva zvipenyu dzakasiyana mavambo. Saka, muna yepamusoro zvinomera nemhuka reshiyo (G + C) / (A + T) dzinosiyana zvishoma uye ane ukoshi kupfuura 1. Nokuti tusingaoneki specificity coefficient dzinosiyana munzvimbo - kubva 0.35 kusvikira 2,70. Zvisinei, masero somatic imwe mhando DNA ane chete nucleotide nziyo, kureva. E. Tinogona kutaura kuti zviri GC yegwara nezvigadziko DNA mumwe dzemarudzi akafanana.

Kutsunga heterogeneity pamusoro nucleotide Zvinoumba DNA pamwero wenyika specificity haapi ruzivo pamusoro wayo chaivo ehupfumi. Munguva ichangopfuura, nokuda dzakasiyana chaizvo nucleotide kutevedzana ari polynucleotide cheni migove. Izvi zvinoreva kuti majini mashoko encoded mu DNA molecules nenzira chaiyo kutevedzana yayo monomeric dzakabatana.

Morekuru reDNA dzine nucleotide sequences aiendeswa mharuro uye kugumiswa dzinotsanagura kwetunhu DNA (kuberekana) RNA usage (transcription) mapuroteni usage (shanduro). Pane nucleotide sequences kuti kushumira kusunga chaizvo simba uye inhibitory pamutemo mamorekuru, uyewo nucleotide sequences kuita izvo kwete kutakura magene ruzivo chero. Kunewo dzakachinja munda, izvo kudzivirira mamorekuru kubva nucleases.

The dambudziko nucleotide sequences DNA usati kugadziriswa zvachose. Kutsunga nucleotide sequences ose nucleic acids ndiyo unoparadza nguva-nzira, iyo inopa kushandiswa nuclease cleavage nzira chaiyo mamorekuru pamusoro yoga zvimedu. Pari, kwakakwana nucleotide kutevedzana pamusoro nitrogenous zvigadziko akasimbisa kuti vazhinji tRNA akasiyana mavambo.

Morekuru reDNA: yechipiri mamiriro

Watson uye Crick kunge zvakagadzirirwa muenzaniso kaviri akamonyoroka pakati deoxyribonucleic acid. Maererano muenzaniso uyu, zviviri polynucleotide ngetani entwine mumwe, nokudaro kusikwa akamonyoroka imwe mhando.

Nitrogenous zvigadziko zvavari riri mukati chivako, uye phosphodiester muzongoza - kunze.

Morekuru reDNA: tertiary mamiriro

The Linear DNA muchitokisi ane chimiro ane elongated Morekuru, zviri mumapepa ari tsindirana marongerwo uye rinotangira chete 1/5 muchitokisi vhoriyamu. Somuenzaniso, kuti DNA kwevanhu chromosome kureba 8 cm uye rakazara zvokuti zvinoenderana mugomba chromosome ane kureba 5 nm. kuisira kwakadaro kunobvira nokuda pamberi helical DNA zvivako. Kubva ichi zvinoreva kuti miviri-nezano DNA akamonyoroka muchadenga kunogona zvimwe kuisira chaiyo tertiary maumbirwo - superhelix. Supercoiled conformation DNA chakanangana okutodza kuvakuru zvipenyu. mamiriro kwakadaro tertiary Kutsigiswa covalent zvisungo kuti amino asidhi residues anoumba mapuroteni kuti vanoumba nucleoprotein zvakaoma (chromatin). Naizvozvo, kuti DNA ine eukaryotic masero chokuita mapuroteni kunyanya chikuru hunhu - histones, uyewo acidic mapurotini uye fosfoproteidami.