This HTML5 document contains 50 embedded RDF statements represented using HTML+Microdata notation.

The embedded RDF content will be recognized by any processor of HTML5 Microdata.

Namespace Prefixes

PrefixIRI
dctermshttp://purl.org/dc/terms/
yago-reshttp://yago-knowledge.org/resource/
n19http://www.ebi.ac.uk/pdbe-site/pdbemotif/
dbohttp://dbpedia.org/ontology/
n9http://dbpedia.org/resource/File:
foafhttp://xmlns.com/foaf/0.1/
n18https://global.dbpedia.org/id/
yagohttp://dbpedia.org/class/yago/
dbthttp://dbpedia.org/resource/Template:
rdfshttp://www.w3.org/2000/01/rdf-schema#
freebasehttp://rdf.freebase.com/ns/
n13http://motif.gla.ac.uk/motif/
rdfhttp://www.w3.org/1999/02/22-rdf-syntax-ns#
owlhttp://www.w3.org/2002/07/owl#
wikipedia-enhttp://en.wikipedia.org/wiki/
provhttp://www.w3.org/ns/prov#
dbchttp://dbpedia.org/resource/Category:
dbphttp://dbpedia.org/property/
xsdhhttp://www.w3.org/2001/XMLSchema#
wikidatahttp://www.wikidata.org/entity/
dbrhttp://dbpedia.org/resource/

Statements

Subject Item
dbr:Nest_(protein_structural_motif)
dbo:wikiPageWikiLink
dbr:Schellman_loop
Subject Item
dbr:Ankyrin_repeat
dbo:wikiPageWikiLink
dbr:Schellman_loop
Subject Item
dbr:C_cap
dbo:wikiPageWikiLink
dbr:Schellman_loop
Subject Item
dbr:Schellman_loop
rdf:type
yago:Design103178782 yago:Decoration103169390 yago:Whole100003553 yago:WikicatProteinStructuralMotifs yago:Artifact100021939 yago:Object100002684 yago:Motif103789014 yago:PhysicalEntity100001930
rdfs:label
Schellman loop
rdfs:comment
Schellman loops (also called Schellman motifs or paperclips) are commonly occurring structural features of proteins and polypeptides. Each has six amino acid residues (labelled residues i to i+5) with two specific inter-mainchain hydrogen bonds (as in lower figure, i) and a characteristic main chain dihedral angle conformation. The CO group of residue i is hydrogen-bonded to the NH of residue i+5 (colored orange in upper figure), and the CO group of residue i+1 is hydrogen-bonded to the NH of residue i+4 (beta turn, colored purple). Residues i+1, i+2, and i+3 have negative φ (phi) angle values and the phi value of residue i+4 is positive. Schellman loops incorporate a three amino acid residue RL nest (protein structural motif), in which three mainchain NH groups (from Schellman loop residu
dcterms:subject
dbc:Organic_chemistry dbc:Protein_structural_motifs
dbo:wikiPageID
41978524
dbo:wikiPageRevisionID
993909616
dbo:wikiPageWikiLink
dbr:Amino_acid dbr:Nest_(protein_structural_motif) dbc:Organic_chemistry dbr:Alpha-helix n9:Schellman_loop.pdf dbr:Hydrogen-bond dbr:Polypeptides dbr:Proteins dbr:Beta_turn dbr:Dihedral_angle dbr:Hydrogen_bond dbr:Carbonyl dbc:Protein_structural_motifs n9:Hydrogen_bond_arrangements_in_Schellman_loops.pdf dbr:Proline dbr:Concave_polygon dbr:Backbone_chain dbr:Glycine dbr:C-terminus
dbo:wikiPageExternalLink
n13:index.html n19:
owl:sameAs
freebase:m.0_r_ld2 wikidata:Q15845157 n18:ZaKx yago-res:Schellman_loop
dbp:wikiPageUsesTemplate
dbt:Reflist
dbo:abstract
Schellman loops (also called Schellman motifs or paperclips) are commonly occurring structural features of proteins and polypeptides. Each has six amino acid residues (labelled residues i to i+5) with two specific inter-mainchain hydrogen bonds (as in lower figure, i) and a characteristic main chain dihedral angle conformation. The CO group of residue i is hydrogen-bonded to the NH of residue i+5 (colored orange in upper figure), and the CO group of residue i+1 is hydrogen-bonded to the NH of residue i+4 (beta turn, colored purple). Residues i+1, i+2, and i+3 have negative φ (phi) angle values and the phi value of residue i+4 is positive. Schellman loops incorporate a three amino acid residue RL nest (protein structural motif), in which three mainchain NH groups (from Schellman loop residues i+3 to i+5) form a concavity for hydrogen bonding to carbonyl oxygens. About 2.5% of amino acids in proteins belong to Schellman loops. Two websites are available for examining small motifs in proteins, Motivated Proteins: [1]; or PDBeMotif: [2]. The majority of Schellman loops (82%) occur at the C-terminus of an alpha-helix such that residues i, i+1, i+2 and i+3 are part of the helix. Over a quarter of helices (28%) have a C-terminal Schellman loop. Occasional Schellman loops occur with seven instead of six residues. In these, the CO group of residue i is hydrogen-bonded to the NH of residue i+6, and the CO group of residue i+1 is hydrogen-bonded to the NH of residue i+5. Rare “left-handed” six-residue Schellman loops occur; these have the same hydrogen bonds, but residues i+1, i+2, and i+3 have positive φ values while the φ value of residue i+4 is negative; the nest is of the LR, rather than the RL, kind. Amino acid propensities for the residues of the common type of Schellman loop have been described. Residue i+4 is the one most-highly conserved; it has positive φ values; 70% of amino acids are glycine and none are proline. Consideration of the hydrogen bonding in the nests of Schellman loops bound to mainchain oxygens reveals two main types of arrangement: 1,3-bridged or not. In one (lower figure, ii) the first and third nest NH groups are bridged by an oxygen atom. In the other (lower figure, iv) the first NH group is hydrogen bonded to the CO group of an amino acid four residues behind in the sequence, and none of the nest NH groups are bridged. It seems that Schellman loops are less homogeneous than might have been expected. The original Schellman criteria result in the inclusion of features not now regarded as Schellman loops. A newer set of criteria is given in the first paragraph.
prov:wasDerivedFrom
wikipedia-en:Schellman_loop?oldid=993909616&ns=0
dbo:wikiPageLength
9679
foaf:isPrimaryTopicOf
wikipedia-en:Schellman_loop
Subject Item
dbr:Schellman_loop_(protein_structural_motif)
dbo:wikiPageWikiLink
dbr:Schellman_loop
dbo:wikiPageRedirects
dbr:Schellman_loop
Subject Item
wikipedia-en:Schellman_loop
foaf:primaryTopic
dbr:Schellman_loop