Plasmid - plasmids umsebenzi ...

Lesi sihloko iqukethe ulwazi mayelana izakhiwo ongaqondakali futhi eziyinkimbinkimbi amangqamuzana ezahlukene, ngokuvamile amagciwane - plasmids. Lapha uzothola ulwazi isakhiwo sabo, injongo, izindlela ukufanisana, izici jikelele kanye nokunye okuningi.

I plasmids babe

Plasmid - DNA molecule ukuthi unesikhathi usayizi amancane isikhundla ngokomzimba uhlukane cell chromosome uhlobo ocwaningweni. Bangakwazi ezizimele ukufanisana inqubo. Ngokuyinhloko plasmid ezitholakala eziphilayo virus. Ngaphandle, abaprofethi bamanga ngale molecule kokuba double balahleke ifomu isiyingi. Kakhulu plasmid ezingavamile ingatholakala archaea futhi eukaryotes.

Ngokuvamile, ama-bacterium plasmids aqukethe ukwaziswa kwezakhi zofuzo ezingaba ngcono ukumelana zangaphandle imvelo izici kubathinta ezithinta isimo umzimba lapho ukuthi akuphi. Ngamanye amazwi, lo plasmid kungehlisa ukusebenza kwamaphilisi ngenxa ukuzinza anda ngobuningi amagciwane uqobo. inqubo ngokudlulisela plasmids namagciwane amagciwane ngokuvamile atholakala. Plasmids - kukhona timphawu tesakhiwo ukuthi kukhona izindlela eziphumelelayo ngokudlulisela ukwaziswa kwezakhi zofuzo ngendlela evundlile.

J. Lederberg - isazi samangqamuzana ezinto eziphilayo, isazi sesayensi odabuka e-United States, owethulwa nomqondo plasmid ngo-1952.

Ubukhulu ntathu plasmids nezinombolo zabo

Plasmid - isakhiwo kokuba ezihlukahlukene osayizi. Ifomu kulencane ingaqukatha kungathi izinkulungwane ezimbili base ngazimbili noma ngaphansi, kanti enye ifomu ezinkulu plasmids encompass abangamakhulu ezinkulungwane eziningana uhlobo base pair. Ukwazi lokhu ikuvumela ukuba udwebe umugqa phakathi megaplazmidami kanye mini-chromosome. Kukhona ama-bacterium ezingaba ihlanganise izinhlobo ezahlukene plasmids. Kulokhu, isamba nesidoda okunikelwe lingadlula ubukhulu ezibonakalayo kwama-cell aphethe.

Isibalo amakhophi plasmids okuyizinto iseli esifanayo, ingahluka kakhulu. Ngokwesibonelo, kwelinye iseli kungase kube kuphela ambalwa, kanti eziningi nezinye plasmids yohlobo olufanayo kufika ku amashumi noma amakhulu. Isibalo sabo ngenxa ubunjalo ukufanisana.

Plasmid - izakhi yeselula kwesakhiwo uyakwazi ukufanisana ezizimele. Okusho ukuthi ungakwazi ukuphindaphinda bebodwa, ngaphandle kokuba kuncike ukulawula chromosome. Ngesikhathi esifanayo, le-chromosome uyakwazi ukulawula ngokwabo plasmids. Endabeni ukulawula okuqinile inani plasmid ziphindaphindwe ngokuvamile encane, mayelana 1-3. Plasmids osayizi amancane kusengozini futhi buthaka lokulawula izingqondo ungakha amakhophi angaphezu.

ukufanisana

plasmid Amagcikwane uyakwazi ukufanisana ezizimele. Nokho, lokhu nqubo ingaphansi degrees lokulawula chromosomal obuhlukahlukene. Lokhu kungenxa yokungabi ezinye zezakhi zofuzo kubalulekile. Ngenxa yalokhu enzyme yeselula afakiwe plasmid ukufanisana.

ukufanisana isinyathelo luhlukaniswe Ukuqalwa isinyathelo, ukunwebeka futhi inqamule. DNA polymerase iqala ukufanisana kuphela ngemva seeding usebenzisa primer. Okokuqala wesifunda evulekile kwenzeka futhi kwakhiwa priming le RNA, kulandele okuncane omunye emaketangeni is futhi khulula 3`-OH sekupheleni.

Ezimweni eziningi, esigabeni Ukuqalwa kwenzeka ngaphansi isenzo catalysts amaprotheni okubhalwe yi plasmid. Ngezinye izikhathi lezi amaprotheni efanayo ongangena primer inqubo vіrabotki.

Ukunwebeka kwenzeka golofermenta ngokusebenzisa i-DNA polymerase III (ngezinye izikhathi mina) kanti ezinye amaprotheni yeselula, owakhiwa replisome.

Ukupheliswa ukufanisana usungaqala kuphela uma izimo ezithile ziyafezwa.

Izimiso ze-control ukufanisana

Control ukufanisana izindlela wenziwa at the stage of Ukusungula ukufanisana. Lokhu kukuvumela ukuba ugcine inani plasmids ngobungako esiqinile. Ukuze i-molecule uyakwazi kokuqaphela lokhu, yilezi:

1. RNA kokuba polarity okuphambene.
2. DNA - ukulandelana (Iteron).
3. RNA kokuba polarity okuphambene, namaprotheni.

Lezi izindlela kubangele ukuvama uphinda lokuphinda plasmids ngaphakathi imijikelezo cell, nabo sokurekhoda enye ngeziphambeko kusukela imvamisa kuyinsakavukela.

Izinhlobo ukufanisana indlela

Kukhona izindlela ezintathu ukufanisana ka plasmids:

1. Theta indlela siqukethe unwinding isigaba 2 wesifunda abazali RNA zamagama primer ngoba umucu ngamunye, ukufanisana eziqalisa ngezithukuthuku ukwanda kwe-covalent uhlobo PrNK kuwo womabili ngamaketanga kanye synthesis DNA ohambelana phezu kwabazali uchungechunge izifunda. Naphezu kweqiniso lokuthi inqubo yokuthola izinhlelo zamagama senzeka ngesikhathi esifanayo, omunye emaketangeni ungumholi, kanti omunye ngemuva.
2. Ukushintshwa uchungechunge - displacement ezisanda kukhiqizwa eyodwa DNA uchungechunge umzali. Kumiswa walokhu indlela is DNA olulodwa uchungechunge amafomu uhlobo esiyingini supercoiled DNA ngamaketanga amabili. DNA komunye uchungechunge liyobuyiselwa kamuva.
3. umbuthano Rolling ukufanisana indlela - igebe owodwa balahleke le-DNA usebenzisa Rep amaprotheni. Ngenxa yalokhu, kuba iqembu 3`-OH, okuyinto uyokwenza njengoba primer. Le ndlela yokwenza senzeka esebenzisa ezihlukahlukene yenethiwekhi amaprotheni cell, isib, a helicase DNA.

Zindlela ukudluliswa

Plasmids uthole esitokisini, usebenzisa eyodwa yezindlela ezimbili. Indlela yokuqala - kusungulwe ukuxhumana phakathi kwengqamuzana futhi bathole ezinye esiphathiswa cell, okuyinto ayiqukethe plasmids okubangelwa inqubo conjugation. Kukhona plasmids conjugative e-bacterium, Gram-HIV futhi Gram-HIV. Indlela yokuqala sihlanganisa okuxhunyanwa ngesikhathi transduction noma ukuguqulwa. Indlela yesibili kwenziwa eyayenziwe ngokwethula plasmids esitokisini, umzimba kumele ukusinda uwukubonakaliswa izakhi zofuzo kumaseli yenethiwekhi, isb amaseli ukuthola amakhono abo.

imisebenzi

Indima plasmids ngokuvamile ukunikeza iseli aphethe izakhiwo ezithile. Ezinye zazo kungaba neze nomthelela izici phenotypic yenkosi yakhe, kanti abanye abangela nkulumo izakhiwo abezindaba, enika eliphakeme kwamanye amangqamuzana efanayo. Lokhu bokuphakama uzosingatha cell kungcono ukuzwa izimo ezingezinhle kwemvelo lapho uhlala. In the ukungabikho plasmids enjalo noma cell ngeke akhule, noma ukhetha ukungabuthinti nhlobo izolahleka.

Plasmid - a Amatebhe ingxenye amaseli. Zenza lenqwaba imisebenzi:

1. WezokuThutha ukwaziswa kwezakhi zofuzo phakathi kwe-conjugation. Ngokuvamile, kwenza F-plasmids.
2. Bakteriotsinogennye ukulawula plasmid amaprotheni zamagama, okungase kuholele kokufa nezinye amagciwane. Lokhu ngokuyinhloko kaKholi plasmids.
3. Hly-Fusion plasmid wahlanganyela hemolysin.
4. Imbangela ukumelana imiphumela of izinsimbi ezisindayo.
5. R-plasmid - kuthuthukisa ukumelana ejenti antibiotic.
6. Ent-plasmid - ivumela synthesize enterotoxins.
7. Ezinye zazo ukwandisa degree of ukumelana emisebeni ye-UV.
8. Plasmids ikoloni antigen uvumele webhaktheriya adhesion zenzeka phezu cell phakathi nomzimba isilwane.
9. Eminye nababamele banesibopho isigaba Strand DNA, okungukuthi, ukugwenywa kanye ukuguqulwa.
10. Plasmids CAM imbangela cleavage camphor, XYL xylene kugaywe plasmid futhi plasmid SAL - salicylate.

Lezi zilwane okucwaningwa ngawo kakhulu

Abantu abaningi kufundvwe kahle property plasmid F, R Kol

F-plasmid - iyona edume kunayo kongativnaya plasmid. Ingabe i episome, ehlanganisa ayizinkulungwane eziyikhulu base pair hlobo. It has iphuzu yabo ukufanisana isiqalo iphuzu ikhefu. Njengezinye izinhlobo plasmids conjugative, wahlanganyela ngamakhodi amaprotheni uyakwazi yizitha okunamathiselwe inqubo pili nezinye izinto eziphilayo legciwane ethile cell udonga.

Ngaphandle ulwazi oluvamile iqukethe loci tra futhi trb, okuyinto ukuhlela ezivamile, operon ebalulekile equkethe abayizinkulungwane eziyikhulu namashumi amathathu nane base ngazimbili. Amangqamuzana elikuleli operon, obhekene ezicini ezihlukahlukene conjugation.

R-plasmid (isici) - kuyinto molecule ye-DNA kanye ine ukuma annular. plasmids okuqukethwe i-DNA ukwaziswa unesibopho ukugeleza futhi zisebenzise inqubo ukufanisana nokudluliselwa izakhiwo ukumelana esitokisini umamukeli. Futhi kutholakale izinga cell ukumelana nemithi ethile. Ezinye R-plasmids kukhona conjugative. Dlulisa R-factor kungenxa transduction ejwayelekile futhi cell division. Bayakwazi adluliselwe emkhatsini zinhlobo ezahlukene komunye nomunye, noma ngisho imindeni.

Kuyinto lolu hlobo plasmids ngokuvamile kubangela izinkinga ukwelapha izifo ezibangelwa amagciwane ngokusebenzisa ejenti-antibiotic ezaziwayo manje.

KaKholi plasmids banesibopho synthesis colicin - amaprotheni ekhethekile singavimbela izinqubo zokukhula nasekuvezeni izithombo zaso ezintsha zama-bacterium, ngaphandle yenethiwekhi.

Isici ngezigaba

Yonke uhlelo ngezigaba yakhiwe ngokuhambisana izakhiwo ezithile plasmids:

1. Izindlela ze-ukufanisana futhi indlela yayo ukuvuza.
2. Ukuba khona nje ububanzi ezivamile abezindaba.
3. Izici ukukopisha inombolo.
4. izici Topological ka plasmids.
5. Ukuhambelana.
6. Yena / plasmid conjugative.
7. Ukuba khona isakhi umaka esisogwini plasmid.

Nokho, noma yimuphi indlela yokwahlukanisa iqukethe iphuzu ukufanisana yokuvula isikweleti.

Izicelo of plasmids

plasmids umsebenzi lapho esetshenziswa indoda indlela ngokwakha ikhophi bakha i-DNA. Plasmids ngokwayo inikeza vector. Amandla ukuvumela ukufanisana ka plasmids lokuphinda DNA isakhi sokuzakhela e esiphathiswa cell. Ukusetshenziswa kabanzi abakuthola genetic engineering. Lokhu legatsha isayensi plasmids zidalwe eyayenziwe ekudluliseni ulwazi lohlobo yofuzo noma yisiphi isenzo nolukhohlisayo ne zofuzo.

Umqondo lezi zingxenye yeselula ezitholakala kulemboni ( "Bioshock"). Plasmids enze umsebenzi izinto ezithile ekwazi lidlulisele izakhiwo eziyingqayizivele emzimbeni. Kubalulekile ukwazi ukuthi plasmids umdlalo ube lutho ukukwenza nanoma yimuphi yangempela. Umdlalo kwenziwa Bhalobhasha uhlobo oluxube RPG, ngokuthi Bioshock, plasmids kukhona izakhi izakhiwo ezithile emzimbeni, futhi bashintshe indlela yabo ngokunikeza superabilities.