Arginine residue

Fig. 6.16 the use of a marker atom on the alpha-carbon in an arginine residue may lead to a significant electrostatic interaction being neglected because the distance between the marker atoms exceeds the cutoff. 

Fig. 12. Tryptic map of it-PA (mol wt = 66,000) showing peptides formed from hydrolysis of reduced, alkylated rt-PA. Separation by reversed-phase octadecyl (C g) column using aqueous acetonitrile with an added acidic agent to the mobile phase. Arrows show the difference between A, normal, and B, mutant rt-PA where the glutamic acid residue, D, has replaced the normal arginine residue, C, at position 275.

Thirty percent of the tumor-derived mutations are in L3, which contains the single most frequently mutated residue, Arg 248. Clearly the interaction between DNA and the specific side chain of an arginine residue inside the minor groove is of crucial importance for the proper function of p53. It is an open question whether this interaction is needed for the recognition of specific DNA sequences, or is required for the proper distortion of the DNA structure, or a combination of both. Other residues that are frequently mutated in this region participate in interactions with loop L2 and stabilize the structures of loops L2 and L3. Mutations of these residues presumably destabilize the structure so that efficient DNA binding can no longer take place. 

GTP-binding protein at an arginine residue which is involved in GTP hydrolysis. ADP-ribosylation thus leads to constitutive activation of Gs. 

Histones are small, basic proteins required to condense DNA into chromatin. They have been first described and named in 1884 by Albrecht Kossel. There are five main histones HI, H2A, H2B, H3 andH4. An octamer of core histones H2A, H2B, H3 andH4 is located inside a nucleosome, the central building block of chromatin, with about 150 base pairs of DNA wrapped around. The basic nature of histones, mediated by the high content of lysine and arginine residues, allows a direct interaction with the acidic phosphate back bone of DNA. The fifth histone HI is located outside at the junction between nucleosomes and is referred to as the linker histone. Besides the main histones, so-called histone variants are known, which replace core histones in certain locations like centromers. 

Histone methylation is a common posttranslational modification fond in histones. Histone methylations have been identified on lysine and arginine residues. In case of lysines S-adenosyl-methionine (SAM) dependent methyl transferases catalyze the transfer of one, two or three methyl groups. Lysine methylation is reversible and lysine specific demethylases have been... 

SNARE motifs spontaneously assemble into SNARE complexes. These consist of a bundle of four intertwined a-helices that are connected by a total of 16 layers of mostly hydrophobic amino acid side chains. In the middle of the bundle, there is a highly conserved and polar 0-layer consisting of three glutamine and one arginine residue. These residues are among the most conserved in the SNARE superfamily and led to a classification of SNAREs into Q- and R-SNAREs, respectively. Different fusion steps require different sets of SNAREs but some SNAREs can participate in different complexes, and some fusion steps involve several SNARE complexes that appear to operate in parallel and independently. 

All rhodopsin-like G-protein-coupled receptors have a conserved arginine residue at the intracellular end of TM3 and this residue is thought to be crucial for G-protein activation. The third intracellular loop determines the class of G-protein activated by the receptor with the second intracellular loop and C-terminus also influencing G-protein binding in some cases. Four classes of G-protein are known ... 

Indirect evidence for the existence of different conformations of H,K-ATPase has been gained by site-selective reagents. Eor example, Schrijen et al. [67,95] demonstrated that Mg increased exposure of an essential arginine residue near the ATP-binding site and Mg " caused an increase in the number of reactive sulfhydryl groups on the enzyme. 

The slow and fast isoenzymes of Ca -ATPase contain 42 and 50 arginine residues, respectively. The C-terminal sequence of the neonatal fast-twitch isoenzyme is Arg-Arg-Lys. There are only four arginine residues in the putative transmembrane helices, which are probably located near the cytoplasmic or luminal surface of the membrane. The remaining arginine residues are distributed in the cytoplasmic domains. 

Mayo KH, Ilyina E, Roongta V, et al. Heparin binding to platelet factor-4. An NMR and site-directed mutagenesis study arginine residues are crucial for binding. Biochem J 1995 312 357-65. 

---