Lactose Permease: Difference between revisions
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===Structure of Lactose Permease=== | ===Structure of Lactose Permease=== | ||
<applet load=" | <applet load="1PV7" size="300" color="white" frame="true" align="right" caption="Lactose Permease" /> | ||
Lactose permease is a transmembrane protein consisting of N- and C- terminal domains, each with six transmembrane helicies symmetrically positioned within the permease. There are six sidechains that play an irreplaceable role in the active transport of lactose through the protien. Three of these sidechains, Glutamic Acid 126, Arginine 144, and Glutamic Acid 269 have been shown to be crucial in substrate binding activities. Arginine 302, Histidine 322, and Glutamic Acid 325 are known to play a significant role in proton translocation(moving the H+ proton) throughout the transport process. Additionally, there are two residues that are suspected to play an important role in the alignment of the galactopyranosyl end of the substrate. These are Cysteine 148 and Tryptophan 151. | <scene name='Lactose_Permease/Beginning/1'>Lactose permease</scene> is a transmembrane protein consisting of N- and C- terminal domains, each with six <scene name='Lactose_Permease/Backbone/1'>transmembrane helicies</scene> symmetrically positioned within the permease. There are six sidechains that play an irreplaceable role in the active transport of lactose through the protien. Three of these sidechains, <scene name='Lactose_Permease/Glu126/1'>Glutamic Acid 126</scene>, <scene name='Lactose_Permease/Arg144/1'>Arginine 144</scene>, and <scene name='Lactose_Permease/Glu269/1'>Glutamic Acid 269</scene> have been shown to be crucial in substrate binding activities. <scene name='Lactose_Permease/Arg302/1'>Arginine 302</scene>, <scene name='Lactose_Permease/His322/1'>Histidine 322</scene>, and <scene name='Lactose_Permease/Glu325/1'>Glutamic Acid 325</scene> are known to play a significant role in proton translocation(moving the H+ proton) throughout the transport process. Additionally, there are two residues that are suspected to play an important role in the alignment of the galactopyranosyl end of the substrate. These are <scene name='Lactose_Permease/Cys148/1'>Cysteine 148</scene> and <scene name='Lactose_Permease/Trp151/1'>Tryptophan 151</scene>. | ||
These sidechains, which make up the active site of the protein, can be found within the large internal hydrophilic cavity of the lactose permease. It is here where the substrate is recieved for transport and it is the location from which it is deposited into the cell. The currently crystalized form of the permease is considered an 'inward-facing' conformation. This implies that the hydrophilic cavity mentioned previously is positioned with the opening towards the cytoplasm of the cell. Conversely, and outward-facing conformation would have the cavity facing the periplasm. | These sidechains, which make up the active site of the protein, can be found within the large internal <scene name='Lactose_Permease/Cavity/1'>hydrophilic cavity</scene> of the lactose permease. It is here where the <scene name='Lactose_Permease/Sugar/1'>substrate</scene> is recieved for transport and it is the location from which it is deposited into the cell. The currently crystalized form of the permease is considered an 'inward-facing' conformation. This implies that the hydrophilic cavity mentioned previously is positioned with the opening towards the cytoplasm of the cell. Conversely, and outward-facing conformation would have the cavity facing the periplasm. | ||