C-terminal regions

Fig. 5. Schematic diagram of the presumed arrangement of the amino acid sequence for the 5-opioid receptor, showing seven putative transmembrane segments three intracellular loops, A three extracellular loops, B the extracellular N-terrninus and the intracellular C-terrninus, where (0) represents amino acid residues common to ] -, 5-, and K-receptors ( ), amino acid residues common to all three opioid receptors and other neuropeptide receptors and (O), other amino acids. Branches on the N-terruinal region indicate possible glycosylation sites, whereas P symbols in the C-terminal region indicate...

Figure 4.5 The polypeptide chain of the enzyme pyruvate kinase folds into several domains, one of which is an a/p barrel (red). One of the loop regions in this barrel domain is extended and comprises about 100 amino acid residues that fold into a separate domain (blue) built up from antiparallel P strands. The C-terminal region of about 140 residues forms a third domain (green), which is an open twisted a/p structure.

Figure 6.12 (a) Schematic diagram of one subunit of GroEL. The polypeptide chain is folded info three domains. The equatorial domain (green) is the largest domain, comprising 10 a helices, and is built up from both the N-tetminal and the C-terminal regions. 

Antibodies reacting with the N- and C-terminal regions of the Ca -A TPase... 

Essentially identical conclusions arose from the studies of Matthews et al. [138], An anti-peptide antibody directed against the cytoplasmically exposed C-terminal region of the Ca " -ATPase (985-994) reacted freely in native sarcoplasmic reticulum, in agreement with earlier observations [137], while the antibody directed against the putative luminal loop (877-888) reacted strongly only after solubilization of sarcoplasmic reticulum with Ci2Eg, Purified ATPase preparations reacted freely with both antibodies under both conditions. A 30-kDa protease-resistant fragment obtained... 

Parales JV, RE Parales, SM Resnick, DT Gibson (1998) Enzyme specificity of 2-nitrotoluene 2,3-dioxygenase from Pseudomonas sp. strain JS42 is determined by the C-terminal region of the a subunit of the oxygenase component. / Sacfeno/ 180 1194-1199. 

Figure 40 13C CPMAS (left) and DDMAS (right) NMR spectra of [3-13C]Ala-ppR alone (a and b) and truncated ppR (1-220) (c and d) reconstituted in egg PC bilayer, respectively. 13C NMR signals from the C-terminal region in ppR are shown in the grey (a and b) and arrows (c and d). The resonance peak at 14.1 ppm is ascribed to the methyl carbon peak of egg PC as shown by the asterisk. From Ref. 215 with permission.

Mutagenesis studies have established that the C-terminal region of the // and S receptors is not essential for the receptors to couple to adenylyl cyclase [131, 132]. The remaining intracellular domains of the opiate receptors have almost identical amino acid sequences. As a consequence, it is likely that the intracellular loops are the main regions of the opiate receptor involved in G protein coupling and effector system regulation. 

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