Glycosaminoglycan xylosylkinase (EC 2.7.1.-) (Xylose kinase)
1_MKLKQ 6_ RVVLL 11_ AILLV 16_ IFIFT 21_ KVFLI 26_ DNLDT 31_ SAANR 36_ EDQRA 41_ FHRMM 46_ TGLRV 51_ ELAPK 56_ LDHTL 61_ QSPWE 66_ IAAQW 71_ VVPRE 76_ VYPEE 81_ TPELG 86_ AVMHA 91_ MATKK 96_ IIKAD 101_ VGYKG 106_ TQLKA 111_ LLILE 116_ GGQKV 121_ VFKPK 126_ RYSRD 131_ HVVEG 136_ EPYAG 141_ YDRHN 146_ AEVAA 151_ FHLDR 156_ ILGFH 161_ RAPLV 166_ VGRFV 171_ NLRTE 176_ IKPVA 181_ TEQLL 186_ STFLT 191_ VGNNT 196_ CFYGK 201_ CYYCR 206_ ETEPA 211_ CADGD 216_ IMEGS 221_ VTLWL 226_ PDVWP 231_ LQKHR 236_ HPWGR 241_ TYREG 246_ KLARW 251_ EYDES 256_ YCDAV 261_ KKTSP 266_ YDSGP 271_ RLLDI 276_ IDTAV 281_ FDYLI 286_ GNADR 291_ HHYES 296_ FQDDE 301_ GASML 306_ ILLDN 311_ AKSFG 316_ NPSLD 321_ ERSIL 326_ APLYQ 331_ CCIIR 336_ VSTWN 341_ RLNYL 346_ KNGVL 351_ KSALK 356_ SAMAH 361_ DPISP 366_ VLSDP 371_ HLDAV 376_ DQRLL 381_ SVLAT 386_ VKQCT 391_ DQFGM 396_ DTVLV 401_EDRMP
1: Responsible for the 2-O-phosphorylation of xylose in the glycosaminoglycan-protein linkage region of proteoglycans thereby regulating the amount of mature GAG chains. Sulfated glycosaminoglycans (GAGs), including heparan sulfate and chondroitin sulfate, are synthesized on the so-called common GAG-protein linkage region (GlcUAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser) of core proteins, which is formed by the stepwise addition of monosaccharide residues by the respective specific glycosyltransferases. Xylose 2-O-phosphorylation may influence the catalytic activity of B3GAT3 (GlcAT-I) which completes the precursor tetrasaccharide of GAG-protein linkage regions on which the repeating disaccharide region is synthesized