Sandbox Reserved 1794: Difference between revisions

NTCP is one continuous polypeptide chain containing <scene name='95/952722/Labeled_9_helices/5'>9 transmembrane alpha helices</scene>. The N-terminus of the polypeptide chain is found on the extracellular region of the plasma membrane while the C-terminus is located on the intracellular region. There are <scene name='95/952722/Ntcp_core_domain-_blue/9'>Two distinct domains</scene> within the quaternary structure of NTCP: a core domain and a panel domain both being a part of the same polypeptide chain (Fig. 2). The <scene name='95/952722/Ntcp_core_domain-_blue/8'>core domain</scene> <font color='#6060ff'><b>(blue)</b></font> includes 6 transmembrane &alpha; helices (TM2-4 and TM7-9) and demonstrates [https://en.wikipedia.org/wiki/Protein_structure two-fold pseudosymmetry].  The <scene name='95/952722/Ntcp_panel_domain-_red/4'>panel domain</scene> <font color='red'><b>(red)</b></font> consists of 3 transmembrane &alpha; helices (TM1 and TM5-6) and does not display symmetry. Within the core domain, there is a unique crossover between TM-3 and TM-8 that is known as the <scene name='95/952722/Ntcp_x_motif/8'>X motif</scene>. This motif is important because this is where the transporter's substrate binding site is located, and within this motif lies essential residues that aid in the conformational change that NTCP undergoes. The core and panel domains are connected by both extracellular and intracellular <scene name='95/952722/Connector_helices/5'>connector helices</scene> that are separate from the nine transmembrane &alpha; helices.