Qhov sib txawv tseem ceeb ntawm CDS thiab ORF yog CDS yog qhov tseeb nucleotide ib ntu ntawm cov noob uas txhais ua cov protein thaum ORF yog qhov sib luag ntawm DNA uas pib nrog kev txhais lus pib (pib codon) thiab xaus nrog ib qho translation termination site (stop codon).
Ib tus noob muaj cov kab ke coding (CDS). Nws muaj tag nrho exons ntawm cov noob thiab pib codon thiab nres codon. Nws yog qhov tseeb ntawm cov noob uas txhais thiab tsim cov protein. Qhib cov ntawv nyeem los yog ORF yog cov kab ke nucleotide nyob nruab nrab ntawm qhov pib codon thiab nres codon. Tsis muaj codon nres nyob rau hauv ib qho ORF cuam tshuam cov noob caj noob ces uas txhais ua cov protein. Hauv prokaryotes, CDS thiab ORF ntawm cov noob yog tib yam.
CDS yog dab tsi?
CDS lossis coding sequence yog ib feem ntawm cov noob uas tau txhais ua cov protein. Nws suav nrog exons thiab ob codons hu ua AUG codon thiab nres codon. CDS tsis muaj ob thaj tsam UnTranslated: 5' UTR thiab 3 UTR. Ntxiv mus, introns tsis suav nrog hauv CDS.
Daim duab 01: Coding Sequence
Thaum muab piv nrog tag nrho cov genome ntawm ib tus neeg, coding sequences yog ib feem me me. Coding sequence muaj qhov tsim nyog nucleotide sequence los ua cov amino acid sequence ntawm cov protein. Yog li, CDS yog cov ntsiab lus exons uas tuaj yeem muab faib ua nucleotide triplets lossis codons. Codons ua rau muaj cov amino acids.
ORF yog dab tsi?
Qhib nyeem ntawv lossis ORF yog qhov txuas txuas ntxiv ntawm nucleotide ib ntus uas pib nrog pib codon thiab xaus nrog nres codon. Hauv cov lus yooj yim, ORF yog hais txog thaj tsam ntawm nucleotide ib ntus nyob nruab nrab ntawm qhov pib thiab nres codons. Nyob rau hauv nruab nrab, tsis muaj nres codon cuam tshuam ORF. Lub nucleotide ib ntus ntawm pib thiab nres codon encodes rau cov amino acids. Feem ntau, pib codon yog ATG thaum nres codons yog TAG, TAA, thiab TGA. ORF muab cov protein ua haujlwm zoo thaum sau thiab txhais. Li no, ORF suav nrog pib codon, ob peb codons hauv nruab nrab thaj tsam thiab nres codon. Interestingly, ORF muaj qhov ntev uas yuav muab faib los ntawm peb.
Daim duab 02: Qhib Nyeem Ntawv
Nyob rau hauv prokaryotes, txij li tsis muaj introns, ORF yog cov txheej txheem coding ntawm ib cov noob uas sau ncaj qha rau hauv mRNA. Yog li, CDS thiab PRF yog tib yam hauv prokaryotes. Thaum tshawb nrhiav cov noob hauv prokaryotes, nws yooj yim los kuaj xyuas ORF thiab pom cov noob hauv prokaryotes. Hauv eukaryotes, txij li muaj cov introns, ORF yog cov txheej txheem codon uas tsim tom qab ua tiav lossis RNA splicing. ORF yog ib qho ntawm cov pov thawj uas pab cov noob kwv yees ntev npaum li ORF yuav yog ib feem ntawm cov noob.
Dab tsi yog qhov zoo sib xws ntawm CDS thiab ORF?
- Nyob rau hauv prokaryotes, CDS thiab ORF yog tib yam.
- Ob leeg muaj pib codon thiab nres codon.
- Lawv muaj cov nucleotides uas tuaj yeem muab faib ua peb.
- Thaum lawv txhais, lawv tsim cov amino acid sequences.
Qhov txawv ntawm CDS thiab ORF yog dab tsi?
CDS yog qhov tseeb ntawm cov noob uas txhais ua cov protein thaum ORF yog qhov ncab ntawm DNA ntawm qhov pib codon thiab nres codon. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm CDS thiab ORF. Tsis tas li ntawd, CDS tsis muaj introns, tab sis ORF yuav muaj introns. CDS transcripts tag nrho rau hauv mRNA ua tiav thaum ORF tuaj yeem yog ib feem ntawm mRNA ib ntus. Yog li, qhov no yog lwm qhov sib txawv ntawm CDS thiab ORF.
Hauv qab infographic tabulates ib sab ntawm qhov sib txawv ntawm CDS thiab ORF.
Summary – CDS vs ORF
CDS thiab ORF yog ob qho tseem ceeb ntawm cov noob. CDS hais txog thaj av tiag tiag ntawm DNA uas txhais ua cov protein. ORF yog ib ntu ntawm DNA uas pib nrog pib codon "ATG" thiab xaus nrog ib qho ntawm peb qhov kev txiav tawm codons (TAA, TAG lossis TGA). ORF tej zaum yuav yog ib feem ntawm tag nrho mRNA ntawm ib lub noob. Txawm li cas los xij, cov txheej txheem coding ntawm ib cov noob sau los ua kom tiav mRNA ib ntus. Txhua CDS yog ORFs. Tab sis tsis yog txhua ORFs yog CDSs. Yog li, qhov no qhia txog qhov sib txawv ntawm CDS thiab ORF.
