Qhov sib txawv tseem ceeb ntawm halorhodopsin thiab bacteriorhodopsin yog tias halorhodopsin yog lub teeb-tsav chloride twj pom nyob rau hauv archaea thaum bacteriorhodopsin yog lub teeb-tsav proton twj pom nyob rau hauv archaea.
Halorhodopsin thiab bacteriorhodopsin yog heptahelical membrane proteins. Lawv tseem hu ua archaea rhodopsins. Feem ntau, ob qho tib si no muaj nyob rau hauv cov ntshav membrane, ib feem ntawm Halobacterium salinarum cell membrane. Halorhodopsin yog lub teeb-tsav chloride twj tso kua mis uas tso cai rau ions ntws los ntawm sab nraud mus rau sab cytoplasmic. Ntawm qhov tod tes, bacteriorhodopsin yog lub teeb-tsav proton twj tso kua mis uas tso cai rau ions ntws los ntawm sab cytoplasmic mus rau sab extracellular. Yog li ntawd, halorhodopsin thiab bacteriorhodopsin yog ob lub teeb-tsav ion pob pom nyob rau hauv archaea, feem ntau tshwj xeeb hauv halobacteria.
Halorhodopsin yog dab tsi?
Halorhodopsin yog ib qho retinal protein los ntawm archaeon Halobacterium salinarum, uas siv lub zog ntawm lub teeb ntsuab (500 txog 650nm) los thauj chloride ions mus rau hauv lub cell tiv thaiv lub peev xwm ntawm daim nyias nyias. Kev noj cov poov tshuaj chloride los ntawm cov hlwb los ntawm cov twj tso kua mis ions zoo li halorhodopsin yog qhov tsim nyog los tswj osmotic tshuav nyiaj li cas thaum lub sij hawm loj hlob ntawm tes. Ntxiv mus, lub teeb-tsav anion twj tso kua mis txuag tau ntau npaum li cas ntawm metabolic zog. Halorhodopsin folds rau hauv xya-transmembrane helix topology nrog luv luv interconnecting loops. Cov helices (lub npe A mus rau G) yog teem nyob rau hauv ib tug arc-zoo li tus qauv thiab nruj nreem nyob ib ncig ntawm ib tug retinal molecule uas yog covalently khi ntawm ib tug Schiff puag mus rau ib tug conserved lysine amino acid (Lys-242) ntawm helix G. Qhov hla ntawm halorhodopsin. nrog residues yog ib qho tseem ceeb rau kev hloov chloride. Nws yog txoj hauv kev uas yuav tshwm sim ntawm anion.
Daim duab 01: Halorhodopsin
Kev nqus ntawm photon los ntawm halorhodopsin pib lub voj voog catalytic, uas ua rau kev thauj cov anion mus rau hauv lub cell. Lub voj voog tuaj yeem piav qhia txog rau theem ntawm isomerisation (I), ion thauj (T), thiab kev nkag mus tau (hloov S). Tsis tas li ntawd, ib txoj hauv kev tseem ceeb rau kev soj ntsuam ntawm cov qauv halorhodopsin thiab kev ua haujlwm yog qhov ua tau ntawm kev tsim cov protein tshwj xeeb los ntawm qhov chaw qhia mutagenesis thiab homologous overexpression.
YBacteriorhodopsin yog dab tsi?
Bacteriorhodopsin yog lub npe hu ua lub teeb-tsav proton twj tso kua mis hauv archaea xws li Halobacterium salinarum. Bacteriorhodopsin yog cov protein siv los ntawm archaea, tshwj xeeb tshaj yog los ntawm halobacteria, chav kawm ntawm Euryarchaeota. Nws ua raws li lub twj tso kua mis proton uas ntes lub teeb lub zog thiab siv lub zog no los txav cov protons hla cov membrane tawm ntawm lub cell. Cov txiaj ntsig proton gradient yog tom qab hloov mus rau hauv tshuaj lom neeg lub zog.
Daim duab 02: Bacteriorhodopsin
Bacteriorhodopsin yog ib qho 27 kDa integral membrane protein. Lub ntsiab lus rov qab ntawm lub hexagonal lattice yog tsim los ntawm peb txoj hlua hlau zoo tib yam, txhua qhov tig los ntawm 120 degrees txheeb ze rau lwm tus. Tsis tas li ntawd, txhua lub monomer muaj xya transmembrane alpha-helices thiab ib qho ntxiv cellular ntsib ob-stranded beta-daim ntawv. Tsis tas li ntawd, cov protein motive quab yuam tsim los ntawm qhov retinal protein yog siv los ntawm ATP synthase los tsim ATP. Yog li ntawd, los ntawm kev nthuav tawm cov kab mob bacteriorhodopsin, archaea hlwb muaj peev xwm ua ke ATP thaum tsis muaj cov pa roj carbon.
Dab tsi yog qhov zoo sib xws ntawm Halorhodopsin thiab Bacteriorhodopsin?
- Halorhodopsin thiab bacteriorhodopsin belongs rau lub tsev neeg ntawm heptahelical membrane proteins.
- ob leeg yog cov proteins uas muaj qhov muag pom.
- Lawv tseem hu ua archaea rhodopsins.
- Lawv yog lub teeb-tsav ion pob.
- Ob leeg muaj nyob rau hauv cov ntshav ntshav, ib feem ntawm Halobacterium salinarum cell membrane.
- Lawv muaj cov haujlwm tshwj xeeb uas tseem ceeb heev rau kev muaj sia nyob halobacteria.
Qhov txawv ntawm Halorhodopsin thiab Bacteriorhodopsin yog dab tsi?
Halorhodopsin yog lub teeb-tsav chloride twj pom nyob rau hauv archaea, thaum bacteriorhodopsin yog lub teeb-tsav proton twj pom nyob rau hauv archaea. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm halorhodopsin thiab bacteriorhodopsin. Tsis tas li ntawd, halorhodopsin yog lub teeb-tsav chloride twj tso kua mis uas tso cai rau ions ntws los ntawm cov cellular mus rau sab cytoplasmic. Ntawm qhov tod tes, bacteriorhodopsin yog lub teeb-tsav proton twj tso kua mis uas tso cai rau ions ntws los ntawm cytoplasmic mus rau sab extracellular.
Cov hauv qab no qhia txog qhov sib txawv ntawm halorhodopsin thiab bacteriorhodopsin hauv daim ntawv tabular rau ib sab ntawm kev sib piv.
Summary – Halorhodopsin vs Bacteriorhodopsin
Halorhodopsin thiab bacteriorhodopsin yog ob lub teeb-tsav ion pob pom nyob rau hauv archaea, tshwj xeeb tshaj yog halobacteria. Halorhodopsin yog lub teeb-tsav chloride twj tso kua mis, thaum bacteriorhodopsin yog lub teeb-tsav proton twj tso kua mis. Halorhodopsin tso cai rau ion ntws los ntawm extracellular mus rau sab cytoplasmic. Nyob rau hauv sib piv, bacteriorhodopsin tso cai ion ntws los ntawm lub cytoplasmic mus rau sab extracellular. Yog li, qhov no qhia txog qhov sib txawv ntawm halorhodopsin thiab bacteriorhodopsin.
