Qhov Tseem Ceeb Qhov txawv - Histone vs Nonhistone Proteins
Chromatin yog daim ntawv condensed ntawm DNA hauv chromosomes. Nws yog ib tug complex ntawm DNA thiab proteins. Proteins muab cov qauv rau chromatin thiab stabilize DNA nyob rau hauv lub me me ntim ntawm lub nucleus. Proteins koom nrog hauv stabilizing chromatin qauv yog ob hom npe hu ua histone proteins thiab nonhistone proteins. Qhov sib txawv tseem ceeb ntawm histone thiab nonhistone proteins yog cov proteins histone yog cov spools uas DNA khi thaum nonhistone proteins muab cov qauv scaffolding rau DNA. Histone thiab nonhistone proteins ua hauj lwm ua ke los npaj thiab tswj chromosomes.
Histone Proteins yog dab tsi?
Histone proteins raug xa mus ua cov protein tseem ceeb ntawm chromatin. Cov proteins no muab cov qauv tseem ceeb rau cua DNA thiab txo nws qhov ntev los ua chromatin. Histone proteins ua raws li kev sib tw uas DNA cua thiab stabilizes. Yog li ntawd, lawv yog qhov tseem ceeb heev hauv kev teeb tsa chromosomes thiab ntim cov khoom siv caj ces hauv lub nucleus. Yog tias tsis muaj cov proteins histone, chromosomes yuav tsis muaj nyob thiab tsis muaj DNA yuav ncab mus rau qhov ntev ua rau lawv nyuaj rau nrhiav tau hauv cov nucleus.
Histone cov proteins ua haujlwm nrog cov proteins uas tsis yog-histone txhawm rau txhim kho cov qauv DNA. Lub xub ntiag ntawm nonhistone proteins yog qhov tseem ceeb rau kev ua haujlwm ntawm histone proteins. Histone proteins dhau los ua cov tseem ceeb ntawm cov protein molecules los tsim cov nucleosomes uas yog ib feem ntawm chromatin. Lub nucleosome yog tsim los ntawm yim histone proteins thiab DNA. Kev tsim ntawm nucleosome yog ua los ntawm histone proteins ua raws li cov spools rau DNA rau cua. Histone proteins kuj koom nrog hauv kev tswj cov noob. Lawv pab tswj cov noob qhia. Histone proteins tau txais txiaj ntsig zoo hauv cov tsiaj, tsis zoo li cov proteins uas tsis yog tshuaj.
Daim duab 01: Histone proteins
Nonhistone Proteins yog dab tsi?
Nonhistone proteins yog lwm hom proteins uas cuam tshuam nrog DNA hauv cov qauv chromatin. Lawv muab cov qauv scaffolding rau DNA. Lawv ua haujlwm ua ke nrog cov proteins histone los npaj cov chromosomes hauv cov nucleus. Thaum cov histones raug tshem tawm los ntawm chromatin, cov proteins uas tseem tshuav raug xa mus rau cov proteins uas tsis yog-histone. Scaffold proteins, heterochromatin protein 1, DNA polymerase, polycomb, thiab lwm yam motors proteins yog cov piv txwv ntawm nonhistone proteins. Ntxiv rau kev ua raws li scaffolding proteins, nonhistone proteins ua ob peb lwm yam txheej txheem thiab tswj kev ua haujlwm zoo li hauv cov hlwb. Txawm li cas los xij, lub luag haujlwm tseem ceeb ntawm nonhistone cov proteins yog qhov sib txuam ntawm chromatin hauv chromosomes thiab koom haum ntawm chromosomes hauv lub nucleus.
Qhov txawv ntawm Histone thiab Nonhistone Proteins yog dab tsi?
Histone vs Nonhistone Proteins |
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| Histone proteins yog cov protein tseem ceeb ntawm chromatin. | Nonhistone proteins yog cov khoom ntawm chromatin. |
| Major Function | |
| Lawv ua raws li cov DNA rau cua thiab ua kom luv luv. | Lawv ua feem ntau yog scaffolding proteins rau DNA. |
| Type | |
| H1/H5, H2A, H2B, H3, thiab H4 yog hom histones. | Scaffold proteins, Heterochromatin Protein 1, DNA polymerase, Polycomb, thiab lwm yam yog qee hom nonhistones. |
| Kev koom tes ntawm Nucleosome | |
| Histone proteins yog cov proteins tseem ceeb ntawm nucleosome. | Nonhistone proteins tsis yog ib feem ntawm nucleosome. |
| Histone proteins yog khaws cia thoob plaws hom. | Nonhistone proteins tsis tau khaws cia thoob plaws hom. |
| Role in Gene Expression | |
| Histone proteins koom nrog hauv kev tswj cov noob caj noob ces | Nonhistone proteins tsis koom nrog kev cai ntawm noob caj noob ces |
Summary – Histone vs Nonhistone Proteins
Histone thiab nonhistone proteins yog ob hom proteins pom nyob rau hauv chromatin ntawm eukaryotic kab mob. DNA yog qhov txhab nyob ib ncig ntawm cov proteins histone thiab tsim lub hauv paus ntawm chromatin hu ua nucleosome. Lub luag haujlwm tseem ceeb ntawm histone proteins yog ua raws li kev sib txuas rau DNA kom cua thiab ruaj khov. Nonhistone proteins ua raws li cov qauv scaffolding ntawm chromatin. Qhov no yog qhov txawv ntawm histone thiab nonhistone proteins. Yog hais tias histone proteins raug tshem tawm los ntawm chromatin, qhov seem ntawm cov protein tuaj yeem raug xa mus rau cov proteins uas tsis yog-histone. Lawv kuj tseem ceeb hauv kev teeb tsa thiab kev cog qoob loo ntawm chromatin rau hauv chromosomes hauv cov nucleus. Ob leeg cov protein ua haujlwm ua ke. Histones yog lub luag haujlwm rau kev tsim cov qauv ntawm chromosomes thaum nonhistone proteins yog lub luag haujlwm rau kev saib xyuas cov qauv chromosomal.
