Category: Proline
-
The trefoil knot fold is a protein fold in which the protein backbone is twisted into a trefoil knot shape
“Shallow” knots in which the tail of the polypeptide chain only passes through a loop by a few residues are uncommon, but “deep” knots in which many residues are passed through the loop are extremely rare. Deep trefoil knots have been found in the SPOUT superfamily. including methyltransferase proteins involved in posttranscriptional RNA modification in all three domains of life, including bacterium Thermus thermophilus and…
-
Sericin is a protein created by Bombyx mori (silkworms) in the production of silk
Silk is a fibre produced by the silkworm in production of its cocoon. It consists mainly of two proteins, fibroin and sericin. Silk consists of 70–80% fibroin and 20–30% sericin; fibroin being the structural center of the silk, and sericin being the gum coating the fibres and allowing them to stick to each other. Structure Sericin is composed…
-
Indoleamine-pyrrole 2,3-dioxygenase (IDO or INDO) is involved in tryptophan metabolism
Indoleamine-pyrrole 2,3-dioxygenase (IDO or INDO EC 1.13.11.52) is a heme-containing enzyme physiologically expressed in a number of tissues and cells, such as the small intestine, lungs, female genital tract or placenta. In humans is encoded by the IDO1 gene. IDO is involved in tryptophan metabolism. It is one of three enzymes that catalyze the first and rate-limiting step in the kynurenine pathway, the O2-dependent oxidation of L-tryptophan to N-formylkynurenine, the others being indolamine-2,3-dioxygenase 2 (IDO2) and tryptophan 2,3-dioxygenase…
-
Fischer-Fantuzzi L, Vesco C. Deletion of 43 amino acids in the NH2-terminal half of the large tumor antigen of simian virus 40 results in a non-karyophilic protein capable of transforming established cells. Proc Natl Acad Sci U S A. 1985
Abstract We have characterized a simian virus 40 (SV40) mutant, derived from the viral DNA insertion present in simian cell transformants, which carries a deletion affecting the NH2-terminal region of the SV40 large tumor antigen. This mutant protein is 6% smaller than normal, has lost the typical nuclear localization of the SV40 large tumor antigen,…
-
Proline and a few other notes
Proline (symbol Pro or P) is an organic acid classed as a proteinogenic amino acid (used in the biosynthesis of proteins), although it does not contain the amino group -NH2 but is rather a secondary amine. The secondary amine nitrogen is in the protonated form (NH2+) under biological conditions, while the carboxyl group is in the deprotonated −COO− form. The “side chain” from the α carbon connects to the nitrogen forming a pyrrolidine loop, classifying it…
-
Xylose is the first saccharide added to the serine or threonine in the proteoglycan type O-glycosylation
Xylose is the first saccharide added to the serine or threonine in the proteoglycan type O-glycosylation, and, so, it is the first saccharide in biosynthetic pathways of most anionic polysaccharides such as heparan sulfate and chondroitin sulfate. Definitions Proteoglycans are proteins that are heavily glycosylated. The basic proteoglycan unit consists of a “core protein” with one or more covalently attached glycosaminoglycan (GAG) chain(s). The point of attachment is a serine (Ser) residue to which the glycosaminoglycan is joined through…
