Reviewed, UniProtKB/Swiss-Prot Q8T1C6 (GNT1_DICDI)

Names and origin

Protein names

Recommended name:
    [Skp1-protein]-hydroxyproline N-acetylglucosaminyltransferase
    EC=2.4.1.229
Alternative name(s):
    Skp1-HyPro GlcNAc-transferase
    UDP-GlcNAc:Skp1-hydroxyproline GlcNAc-transferase
      Short name=Skp1 GlcNAc-Tase
    UDP-GlcNAc:hydroxyproline polypeptide GlcNAc-transferase
    Glycosyltransferase GnT51

Gene names

Name:	gnt1
Synonyms:	gnt51, gntA
ORF Names:	DDB_G0275699

Organism

Dictyostelium discoideum (Slime mold) [Complete proteome]

Taxonomic identifier

44689 [NCBI]

Taxonomic lineage

Eukaryota › Amoebozoa › Mycetozoa › Dictyosteliida › Dictyostelium

Protein attributes

Sequence length	423 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Catalyzes the attachment of N-acetylglucosamine (GlcNAc) in alpha-linkage onto the 'hydroxyPro-143' residue of Skp1 (fpaA/fpaB). Is the first glycosyltransferase in the Skp1 HyPro modification pathway, which results in a pentasaccharide-linked 'HyPro-143'.
Catalytic activity	UDP-N-acetylglucosamine + [Skp1-protein]-hydroxyproline = UDP + [Skp1-protein]-O-(N-acetyl-D-glucosaminyl)hydroxyproline.
Cofactor	Magnesium.
Enzyme regulation	Requires dithiothreitol (DTT) for activity in vitro. Activated by Tween 20 or Tween 80 in vitro. Inhibited by UMP, UDP, UTP, 4-thio-UMP, Bio-11-UTP, and UDP-Glc but not by uridine, dUDP, dUMP, UDP-hexanolamine, and CTP. Also inhibited by EDTA.
Pathway	Protein modification; protein glycosylation.
Subunit structure	Monomer.
Subcellular location	Cytoplasm.
Domain	The C-terminal 65 amino acids are required for catalytic activity.
Miscellaneous	Present with 4000 molecules/cell.
Sequence similarities	Belongs to the glycosyltransferase 60 family.
Biophysicochemical properties	Kinetic parameters: The low Vmax value suggests that the enzyme may be down-regulated under the assay conditions. KM=0.16 µM for UDP-GlcNAc KM=0.56 µM for Skp1 Vmax=12.6 nmol/h/mg enzyme pH dependence: Optimum pH is 7.5-8. Activity is less than 10% at pH 6.0. Temperature dependence: Optimum temperature is 30-33 degrees Celsius.

Ontologies

Keywords
Cellular component	Cytoplasm
Ligand	Magnesium Metal-binding
Molecular function	Glycosyltransferase Transferase
Technical term	Complete proteome Direct protein sequencing
Gene Ontology (GO)
Biological process	protein amino acid glycosylation Ref.1 Inferred from direct assay. Source: dictyBase
Cellular component	cytoplasm Ref.1 Ref.4 Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	Skp1-protein-hydroxyproline N-acetylglucosaminyltransferase activity Inferred from electronic annotation. Source: EC magnesium ion binding Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 423	423	[Skp1-protein]-hydroxyproline N-acetylglucosaminyltransferase		PRO_0000328555
Regions
	Compositional bias	281 – 290	10	Poly-Asn
	Compositional bias	293 – 323	31	Poly-Asn
	Compositional bias	324 – 331	8	Poly-Ser
	Compositional bias	332 – 343	12	Poly-Asn
	Compositional bias	348 – 357	10	Poly-Asn
Sites
	Metal binding	102	1	Magnesium Probable
	Metal binding	104	1	Magnesium Probable
Experimental info
	Mutagenesis	23	1	K → R: No effect
	Mutagenesis	102	1	D → A: Loss of activity
	Mutagenesis	104	1	H → D: Loss of activity
	Mutagenesis	276	1	L → S: 7% of wild-type activity
	Sequence conflict	23	1	K → R in AAK56291. Ref.1
	Sequence conflict	56	1	F → I in AAK56291. Ref.1
	Sequence conflict	116	1	I → V in AAK56291. Ref.1
	Sequence conflict	276	1	L → W in AAK56291. Ref.1
	Sequence conflict	332	1	N → H in AAK56291. Ref.1
	Sequence conflict	365 – 368	4	LKYN → PNYL in AAK56291. Ref.1

Sequences

	Sequence		Length	Mass (Da)
	Q8T1C6-1 [UniParc]. Last modified June 1, 2003. Version 2. Checksum: 72DA5B7ED438D27D	FASTA	423	49,069
	10 20 30 40 50 60 MNENSIFVSI ISYRDSECQW TIKNLIELAK YKENIFIGVC LQYSMNDDSD NKCFQFNFEE 70 80 90 100 110 120 EYGKNQIRII RMNHTEAKGP CYARALVQQQ LFKGEKYYLQ IDSHMRFVKD WDIEMINQLL 130 140 150 160 170 180 QCKKPNDDNG GMVIDEKAIL TCYPMGYKLP NLIPTHRFPI LLVASGFGEN DGFLRLGGKI 190 200 210 220 230 240 VSKKLIEPCS SLFWVSGFSF SRSDIINSVP YDPNLQYLFF GEEISMSARL FTHGYNFYSP 250 260 270 280 290 300 TKTLIFHLWN RDYRSTFREN NSLEIQKLEE NSKKRLLILF NQNNNNINDN DDNNNNNNNN 310 320 330 340 350 360 NNNNNNNNNN NNNNNNNNNN NNNSSSSSSS SNNNNNNNNN NNNSSSTNNN NNNNNNNDDG 370 380 390 400 410 420 IKIELKYNLG KIKSLDDYSN YCGVDFKNKT INNKGKFGGY YEERETFFMN EIMEYVIKSQ IGI

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Molecular cloning and expression of a UDP-N-acetylglucosamine (GlcNAc):hydroxyproline polypeptide GlcNAc-transferase that modifies Skp1 in the cytoplasm of Dictyostelium." van der Wel H., Morris H.R., Panico M., Paxton T., Dell A., Kaplan L., West C.M. J. Biol. Chem. 277:46328-46337(2002) [PubMed: 12244115] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 160-175, IDENTIFICATION BY MASS SPECTROMETRY, FUNCTION, DOMAIN, MUTAGENESIS OF LYS-23; ASP-102; HIS-104 AND LEU-276.
[2]	"Sequence and analysis of chromosome 2 of Dictyostelium discoideum." Gloeckner G., Eichinger L., Szafranski K., Pachebat J.A., Bankier A.T., Dear P.H., Lehmann R., Baumgart C., Parra G., Abril J.F., Guigo R., Kumpf K., Tunggal B., Cox E.C., Quail M.A., Platzer M., Rosenthal A., Noegel A.A. Nature 418:79-85(2002) [PubMed: 12097910] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: AX4.
[3]	"The genome of the social amoeba Dictyostelium discoideum." Eichinger L., Pachebat J.A., Gloeckner G., Rajandream M.A., Sucgang R., Berriman M., Song J., Olsen R., Szafranski K., Xu Q., Tunggal B., Kummerfeld S., Madera M., Konfortov B.A., Rivero F., Bankier A.T., Lehmann R., Hamlin N. , Davies R., Gaudet P., Fey P., Pilcher K., Chen G., Saunders D., Sodergren E.J., Davis P., Kerhornou A., Nie X., Hall N., Anjard C., Hemphill L., Bason N., Farbrother P., Desany B., Just E., Morio T., Rost R., Churcher C.M., Cooper J., Haydock S., van Driessche N., Cronin A., Goodhead I., Muzny D.M., Mourier T., Pain A., Lu M., Harper D., Lindsay R., Hauser H., James K.D., Quiles M., Madan Babu M., Saito T., Buchrieser C., Wardroper A., Felder M., Thangavelu M., Johnson D., Knights A., Loulseged H., Mungall K.L., Oliver K., Price C., Quail M.A., Urushihara H., Hernandez J., Rabbinowitsch E., Steffen D., Sanders M., Ma J., Kohara Y., Sharp S., Simmonds M.N., Spiegler S., Tivey A., Sugano S., White B., Walker D., Woodward J.R., Winckler T., Tanaka Y., Shaulsky G., Schleicher M., Weinstock G.M., Rosenthal A., Cox E.C., Chisholm R.L., Gibbs R.A., Loomis W.F., Platzer M., Kay R.R., Williams J.G., Dear P.H., Noegel A.A., Barrell B.G., Kuspa A. Nature 435:43-57(2005) [PubMed: 15875012] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: AX4.
[4]	"Identification of a UDP-GlcNAc:Skp1-hydroxyproline GlcNAc-transferase in the cytoplasm of Dictyostelium." Teng-umnuay P., van der Wel H., West C.M. J. Biol. Chem. 274:36392-36402(1999) [PubMed: 10593934] [Abstract] Cited for: FUNCTION, CATALYTIC ACTIVITY, COFACTOR, ENZYME REGULATION, BIOPHYSICOCHEMICAL PROPERTIES, SUBUNIT, SUBCELLULAR LOCATION.

Cross-references

Sequence databases
EMBLGenBankDDBJ	AF375997 Genomic DNA. Translation: AAK56291.1. AC116960 Genomic DNA. Translation: AAM08473.2. AAFI02000013 Genomic DNA. Translation: EAL69600.1.
RefSeq	XP_643451.1.
3D structure databases
ModBase	Search...
Genome annotation databases
GeneID	3394648.
KEGG	ddi:DDB_0185044.
Organism-specific databases
dictyBase	DDB0185044. gnt1.
Family and domain databases
ProtoNet	Search...

Entry information

Entry name

GNT1_DICDI

Accession

Primary (citable) accession number: Q8T1C6
Secondary accession number(s): Q553G2, Q967M5

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 8, 2008
Last sequence update:	June 1, 2003
Last modified:	November 25, 2008
This is version 26 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)