Le degeneracy ye ikhowudi yezofuzo: iziseko

Ikhowudi yezofuzo ichazwa njenge codons, inkqubo usebenzisa ikhowudi ulwazi malunga isakhiwo iiprothini, sizalwa kuzo zonke izinto eziphilayo emhlabeni. Ubuyiselo kubhalo oluqhelekileyo kuthatha amashumi eminyaka, kodwa into yokuba ukho, inzululwazi iqondwa phantse ikhulu. Nsimbi, Okukodwa, oluthambileyo, kwaye ingakumbi degeneracy le ikhowudi yezofuzo zinokubaluleka eziphilayo.

Imbali obafunyanwa

Ingxaki ujiko ulwazi yemfuza ebesoloko iqhosha eziphilayo. Xa isakhiwo matrix le ikhowudi yezofuzo, inzululwazi inkqubela kunokuba kancinci. Ekubeni kwafunyanwa J. Watson kunye Crick ngo-1953 Isakhiwo kweleli kabini ye DNA singene kwisigaba yokusombulula isakhiwo ikhowudi ngokwayo, nto leyo eyabangela inkolelo enobungangamsha wendalo. Isakhiwo linear kweziyi kunye DNA ye isakhiwo esifanayo vula ubukho ikhowudi yezofuzo, imbalelwano phakathi zicatshulwa zimbini, kodwa abhalwe ezazibhalwa ngendlela ezahlukeneyo. Ke ukuba alfabhethi kweziyi sele kwaziwa, namanqaku DNA baba ndaba yokufunda eziphilayo, inzululwazi kunye nakwimathematika.

Akukho mfuneko ukuchaza onke amanyathelo isisombululo sale imfihlakalo. experiment ngqo, yaba yaye baqinisekisa ukuba phakathi codons DNA kunye acid ye-protini kukho ecacileyo nethembakeleyo ezigcinwe ngokulandelelana ngo-1964 Charles Janowski kunye S. Brenner. Enye - ngexesha ekufundeni le ikhowudi yezofuzo in vitro (in vitro) usebenzisa ubuchule leeprothini kudibaniso kwiziseko iseli-free.

Ngokupheleleyo ikhowudi uguqulwa E. Coli wabhengezwa ngo-1966, zebhayoloji kule simpoziyam kwi Yomlomo Spring Harbour (USA). Emva koko wavula komsebenzi (degeneracy) of ikhowudi yezofuzo. kuthetha ntoni oku, ezazichazwa kakhulu nje.

kokuhlaziya uyaqhubeka

Ukufumana ezama ilifa ikhowudi data uye waba ngomnye iziganeko ezininzi kakhulu kwinkulungwane yokugqibela. Namhlanje, inzululwazi iyaqhuba ukuba baphonononge ngokunzulu indlela benkqubo lwalusanda encoding kunye neempawu zayo kunye nako ngokugqithiseleyo imiqondiso, oko kuchazwe yipropathi degeneracy ye ikhowudi yezofuzo. Uphononongo eyahlukileyo oshishino - imvelaphi kunye ngendaleko inkqubo eziphathekayo ikhowudi amafa. Ubungqina polynucleotides ezayamanisa (DNA) kunye polypeptides (iiprothini) umfutho kuphuhliso ezinto eziphilayo. Kwaye ukuba, xa ke, ibiotechnology, bioengineering, ezifunyaniswe kulo kufuywe izityalo ekhulayo.

Mfundiso kunye nemithetho

Ekhaya mfundiso ezinto eziphilayo - ulwazi zidluliselwe ukusuka DNA umthunywa RNA, waza naye phezu protini. Kwelinye icala yosasazeko kunokwenzeka ukususela RNA ukuya DNA kunye RNA kwezinye RNA.

Kodwa ke matrix okanye isiseko DNA isoloko. Nazo zonke ezinye iimpawu ezisisiseko ukudlulisela ulwazi - kubonisa yohlobo ukutshintshwa isizalo. Oko kukuthi, ngokwenza ukudluliselwa ukuya Yindibanisela molecule matrix, nto leyo eya kuba enomfanekiso isakhiwo yemfuza.

ikhowudi yezofuzo

Umgca esephepheni isakhiwo zeprotheyini neemolekyuli ngokusebenzisa codons ngokubambisana (ezintathu) nucleotides, leyo kuphela 4 (adein, guanine, cytosine, thymine (uracil)), nto leyo ngokuzenzekelayo ekhokelela kuseko kwezinye neentsontelo nucleotides. Inani elifanayo nucleotides kunye complementarity kwemichiza - oku imeko esingundoqo yokuqaphela enjalo. Kodwa ukuyilwa umgangatho protein molecule ngokuthelekisa ubungakanani nomgangatho monomers ayikho (nucleotides DNA - Iprothini acid asidi). Le ikhowudi yendalo ilifa - inkqubo nokurekhodwa ngokulandelelana nucleotides (codons) acid acid ukulandelelana kwiproteni.

ikhowudi yezofuzo has iipropati ezininzi:

• Triplet.
• Yokuvelela.
• Orientation.
• Disjointness.
• Komsebenzi (degeneracy) of ikhowudi yezofuzo.
• Nsimbi.

Nantsi inkcazo emfutshane, egxininisa ukubaluleka eziphilayo.

Triplet, inkqubela kunye stoplights nokufumaneka

Ngamnye 61 acid sihambisane t kwisemantiki (triplet) nucleotides. ezintathu emithathu musa ulwazi malunga asidi acid kwaye codons stop. nucleotide ngamnye kwikhonkco ulilungu le triplet, kwaye lingekho ngokwalo. Ekupheleni kunye ekuqaleni kwekhonkco of nucleotides ehambelana iproteni olunye, ngaba codons stop. Baqala okanye losasazo stop (i Yindibanisela zinemoletyhule protein).

Okukodwa, yaye omnye-pointedness disjointness

codon ngalinye (triplet) buqonda enye kuphela asidi acid. triplet nganye izimele kwaye akukho zilala phezu ezikufutshane. Enye nucleotide angaba kiso triplet omnye kuphela kwikhonkco. Iprothini yokuqaphela kusoloko kwicala elinye codons stop kuphela, oko elawulwa.

Le komsebenzi we ikhowudi yezofuzo

triplet ngalinye nucleotides buqonda omnye acid acid. Zizonke nucleotides 64, 61 kubo - ekhowudiweyo acid acid (kengoku codon), kunye ezintathu - ngamampunge, okt acid acid akuthethi encoder (ayeke codons). Le komsebenzi (degeneracy) ikhowudi yezofuzo kukuba kwabadlali zingenziwa kwi triplet nganye - ezinkulu (okukhokelela acid acid replacement) kunye ngendeb '(acid musa ukutshintsha iklasi). Kulula ukuba ukubala ukuba xa triplet ingaqhuba kwabadlali 9 (1, 2 no-3 indawo), nucleotide ngalinye kutshintshwa nge-4 - 1 = 3 nezinye lwalo, inani elipheleleyo lamalalela nucleotide kunokwenzeka ziya kuba 61 ukuya ku-9 = 549.

Le degeneracy ye ikhowudi yezofuzo kuboniswa kule yokuba 549 iinketho - kuba ngaphezulu kakhulu kunokuba kuyimfuneko ukuze ulwazi zakodirovki malunga 21 acid. Kule Kwimeko iinketho replacement 549 23 kukhokelela ukuyilwa kwento codon isingxi, 134 + 230 endaweni - ezi kwabadlali 'endala, kwaye 162 - olukhulu.

Silawule degeneracy and exceptions

Ukuba codons ababini ezimbini nucleotide ezifanayo kuqala, le nucleotides eseleyo zinikwa eklasini (purine okanye pyrimidine), ulwazi ethwele acid acid efanayo. Oku kudla degeneracy okanye komsebenzi we ikhowudi yezofuzo. ngaphandle ezimbini - AUA kunye UGA - kuqala buqonda methionine, nangona kwakuza kufuneka isoleucine, kwaye eyesibini - a codon stop, kodwa kwakuza kufuneka uku encoder tryptophan.

Meaning degeneracy kunye nsimbi

Ezi iimpawu ezimbini ikhowudi yezofuzo anexabiso kakhulu eziphilayo. Zonke iipropati ezidweliswe ngasentla uphawu ulwazi yemfuza zonke iintlobo zezinto eziphilayo emhlabeni.

Le degeneracy ikhowudi yezofuzo une encomekayo, njengoko Uphindaphindo okuphindwayo omnye ikhowudi acid acid. Ukongeza, oku kuthetha ukuncitshiswa ebalulekileyo (ukonakala) loMthetho nucleotide yesithathu a codon. Loo ngobuwena kunciphisa izilonda mutational kwi DNA, apho kubandakanya yanyhashwa kubume protein. Oku yindlela zikhusela izinto eziphilayo emhlabeni.