title: Super-motifs and evolution of tandem leucine-rich repeats within the small proteoglycans--biglycan, decorin, lumican, fibromodulin, PRELP, keratocan, osteoadherin, epiphycan, and osteoglycin.
abstract: Leucine-rich repeats (LRRs) with 20-30 amino acids in unit length are present in many proteins from prokaryotes to eukaryotes. The LRR-containing proteins include a family of nine small proteoglycans, forming three distinct subfamilies: class I contains biglycan/PG-I and decorin/PG-II; class II: lumican, fibromodulin, PRELP, keratocan, and osteoadherin; and class III: epiphycan/PG-Lb and osteoglycin or osteoinductive factor. Comparative sequence analysis of the 34 available protein sequences reveals that these proteoglycans have two types of LRRs, which we call S and T. The type S LRR is 21 residues long and has the consensus sequence of xxaPzxLPxxLxxLxLxxNxI. The type T LRR has 26 residues; its consensus sequence is zzxxaxxxxFxxaxxLxxLxLxxNxL. In both "x" indicates variable residue; "z" is frequently a gap; "a" is Val, Leu, or Ile; and I is Ile or Leu. These type S and TLRRs are ordered into two super-motifs--STT with about 73 residues in classes I and II and ST with about 47 residues in class III. The 12 LRRs in the small proteoglycans of I and II are best represented as (STT)4; the seven LRRs of class III as (ST)T(ST)2. Our analyses indicate that classes I/II and III evolved along different paths after the establishment of the precursor ST, and classes I and II also diverged after the establishment of the precursor (STT)4.
authors.affiliation: School of Health Sciences, Sapporo Medical University, Hokkaido, Japan. matusima@shs.sapmed.ac.jp
authors.forename: N
authors.initials: N
authors.lastname: Matsushima
authors.forename: T
authors.initials: T
authors.lastname: Ohyanagi
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: R H
authors.initials: RH
authors.lastname: Kretsinger
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D058578:Biglycan; D002352:Carrier Proteins / Q000737:chemistry; D011508:Chondroitin Sulfate Proteoglycans / Q000737:chemistry; D058575:Decorin; D016326:Extracellular Matrix Proteins / Q000737:chemistry; D000071235:Fibromodulin; D006023:Glycoproteins / Q000737:chemistry; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D007632:Keratan Sulfate / Q000737:chemistry; D007930:Leucine; D000071234:Lumican; D008969:Molecular Sequence Data; D010802:Phylogeny; D011487:Protein Conformation; D011509:Proteoglycans / Q000737:chemistry*; D016415:Sequence Alignment; D000071232:Small Leucine-Rich Proteoglycans
chemical_list: C546884:BGN protein, human; C546885:Bgn protein, mouse; D058578:Biglycan; D002352:Carrier Proteins; D011508:Chondroitin Sulfate Proteoglycans; C546878:DCN protein, human; C546879:Dcn protein, mouse; D058575:Decorin; C119499:EPYC protein, human; C504412:Epyc protein, mouse; D016326:Extracellular Matrix Proteins; C000604330:FMOD protein, human; C000604332:Fmod protein, mouse; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; C490948:KERA protein, human; C000604306:LUM protein, human; C000604307:Lum protein, mouse; D000071234:Lumican; C063488:OGN protein, human; C512906:Ogn protein, mouse; C096382:PRELP protein, human; C490748:Prelp protein, mouse; D011509:Proteoglycans; D000071232:Small Leucine-Rich Proteoglycans; C113360:osteoadherin; D000071235:Fibromodulin; D007632:Keratan Sulfate; D007930:Leucine