Q8W1X2 (PDXK_ARATH) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Pyridoxal kinase
EC=2.7.1.35

Alternative name(s):
Protein SALT OVERLY SENSITIVE 4
Pyridoxal kinase-like protein SOS4
Pyridoxine kinase

Gene names

Name:	PK
Synonyms:	PDXK, SOS4
Ordered Locus Names:	At5g37850
ORF Names:	K18L3_10

Organism

Arabidopsis thaliana (Mouse-ear cress) [Reference proteome]

Taxonomic identifier

3702 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Viridiplantae › Streptophyta › Streptophytina › Embryophyta › Tracheophyta › Euphyllophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › malvids › Brassicales › Brassicaceae › Camelineae › Arabidopsis

Protein attributes

Sequence length	309 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Catalyzes the transfer of a phosphate group from ATP to the 5-hydroxylmethyl group of pyridoxal to form the biologically active pyridoxal phosphate. Ref.7
Catalytic activity	ATP + pyridoxal = ADP + pyridoxal 5'-phosphate.
Cofactor	Divalent cations. Zinc >> cobalt > magnesium > manganese > calcium.
Pathway	Cofactor biosynthesis; B6 vitamer interconversion; pyridoxal 5'-phosphate from pyridoxal: step 1/1.
Subunit structure	Homodimer.
Tissue specificity	Expressed ubiquitously in leaves, stems, roots, flowers and siliques.
Developmental stage	Becomes detectable 60 hours after imbibition of the seeds and remains constant up to 101 hours after imbibition.
Induction	Both long and short transcripts are down-regulated in roots but not in shoots by NaCl and abscisic acid treatment. Under cold stress, the expression of the short transcript is increased while the long one becomes undetectable.
Miscellaneous	Defective pyridoxal kinase results in both salt hypersensitive and root hairless phenotypes.
Sequence similarities	Belongs to the pyridoxine kinase family.
Biophysicochemical properties	Kinetic parameters: KM=98 µM for ATP KM=688 µM for pyridoxal Vmax=1.604 mmol/min/mg enzyme pH dependence: Optimum pH is 6.0. Active from pH 4.5 to 10.5.

Ontologies

Keywords
Coding sequence diversity	Alternative splicing
Ligand	ATP-binding Metal-binding Nucleotide-binding Pyridoxal phosphate Zinc
Molecular function	Kinase Transferase
Technical term	Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological_process	hyperosmotic salinity response Inferred from mutant phenotype Ref.2. Source: TAIR pyridoxal 5'-phosphate salvage Inferred from direct assay Ref.1. Source: TAIR pyridoxine biosynthetic process Traceable author statement Ref.2. Source: TAIR trichoblast differentiation Inferred from mutant phenotype Ref.7. Source: TAIR
Cellular_component	cytosol Inferred from direct assay PubMed 21166475. Source: TAIR
Molecular_function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW pyridoxal kinase activity Inferred from direct assay Ref.1. Source: TAIR
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Isoform 1 (identifier: Q8W1X2-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Isoform 2 (identifier: Q8W1X2-2)

The sequence of this isoform differs from the canonical sequence as follows:
     1-1: M → MPFSFPTTTTTSLPFHKDHNHFNLNRNLRSRNRRM

Note: No experimental confirmation available.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 309	309	Pyridoxal kinase		PRO_0000213341
Regions
	Nucleotide binding	193 – 194	2	ATP By similarity
	Nucleotide binding	221 – 233	13	ATP By similarity
Sites
	Binding site	23	1	Substrate By similarity
	Binding site	58	1	Substrate By similarity
	Binding site	134	1	Substrate By similarity
	Binding site	234	1	Substrate By similarity
Natural variations
	Alternative sequence	1	1	M → MPFSFPTTTTTSLPFHKDHN HFNLNRNLRSRNRRM in isoform 2.		VSP_004654

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 [UniParc]. Last modified December 6, 2002. Version 2. Checksum: 3630575692F2B271	FASTA	309	34,043
	10 20 30 40 50 60 MTTPPVLSLA LPSDTGRVLS IQSHTVQGYV GNKSAVFPLQ LLGYDVDPIN SVQFSNHTGY 70 80 90 100 110 120 PTFKGQVLNG QQLCDLIEGL EANDLLFYTH VLTGYIGSVS FLDTILEVIN KLRSVNPNLT 130 140 150 160 170 180 YVCDPVMGDE GKLYVPEELV HVYREKVVPL ASMLTPNQFE AEKLTGLRIN SEEDGREACA 190 200 210 220 230 240 ILHAAGPSKV VITSITIGGI LLLIGSHQKE KGLKPEQFKI LIHKIPAYFT GTGDLMTALL 250 260 270 280 290 300 LGWSNKYPDN LDKAAELAVS TLQALLRRTL DDYKRAGYDP TSSSLEIRLI QSQEDIRNPK VELKAERYS
	Isoform 2 [UniParc]. Checksum: 58DFE7EF6334C178	FASTA	343	38,167
	10 20 30 40 50 60 MPFSFPTTTT TSLPFHKDHN HFNLNRNLRS RNRRMTTPPV LSLALPSDTG RVLSIQSHTV 70 80 90 100 110 120 QGYVGNKSAV FPLQLLGYDV DPINSVQFSN HTGYPTFKGQ VLNGQQLCDL IEGLEANDLL 130 140 150 160 170 180 FYTHVLTGYI GSVSFLDTIL EVINKLRSVN PNLTYVCDPV MGDEGKLYVP EELVHVYREK 190 200 210 220 230 240 VVPLASMLTP NQFEAEKLTG LRINSEEDGR EACAILHAAG PSKVVITSIT IGGILLLIGS 250 260 270 280 290 300 HQKEKGLKPE QFKILIHKIP AYFTGTGDLM TALLLGWSNK YPDNLDKAAE LAVSTLQALL 310 320 330 340 RRTLDDYKRA GYDPTSSSLE IRLIQSQEDI RNPKVELKAE RYS

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Cloning and characterization of Arabidopsis thaliana pyridoxal kinase." Lum H.-K., Kwok F., Lo S.C.L. Planta 215:870-879(2002) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1), PROTEIN SEQUENCE OF 1-12. Strain: cv. Columbia.
[2]	"The Arabidopsis salt overly sensitive 4 mutants uncover a critical role for vitamin B6 in plant salt tolerance." Shi H., Xiong L., Stevenson B., Lu T., Zhu J.-K. Plant Cell 14:575-588(2002) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORMS 1 AND 2). Strain: cv. Columbia.
[3]	"Structural analysis of Arabidopsis thaliana chromosome 5. VI. Sequence features of the regions of 1,367,185 bp covered by 19 physically assigned P1 and TAC clones." Kotani H., Nakamura Y., Sato S., Asamizu E., Kaneko T., Miyajima N., Tabata S. DNA Res. 5:203-216(1998) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: cv. Columbia.
[4]	The Arabidopsis Information Resource (TAIR) Submitted (APR-2011) to the EMBL/GenBank/DDBJ databases Cited for: GENOME REANNOTATION. Strain: cv. Columbia.
[5]	"Empirical analysis of transcriptional activity in the Arabidopsis genome." Yamada K., Lim J., Dale J.M., Chen H., Shinn P., Palm C.J., Southwick A.M., Wu H.C., Kim C.J., Nguyen M., Pham P.K., Cheuk R.F., Karlin-Newmann G., Liu S.X., Lam B., Sakano H., Wu T., Yu G. , Miranda M., Quach H.L., Tripp M., Chang C.H., Lee J.M., Toriumi M.J., Chan M.M., Tang C.C., Onodera C.S., Deng J.M., Akiyama K., Ansari Y., Arakawa T., Banh J., Banno F., Bowser L., Brooks S.Y., Carninci P., Chao Q., Choy N., Enju A., Goldsmith A.D., Gurjal M., Hansen N.F., Hayashizaki Y., Johnson-Hopson C., Hsuan V.W., Iida K., Karnes M., Khan S., Koesema E., Ishida J., Jiang P.X., Jones T., Kawai J., Kamiya A., Meyers C., Nakajima M., Narusaka M., Seki M., Sakurai T., Satou M., Tamse R., Vaysberg M., Wallender E.K., Wong C., Yamamura Y., Yuan S., Shinozaki K., Davis R.W., Theologis A., Ecker J.R. Science 302:842-846(2003) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1). Strain: cv. Columbia.
[6]	"Full-length cDNA from Arabidopsis thaliana." Brover V.V., Troukhan M.E., Alexandrov N.A., Lu Y.-P., Flavell R.B., Feldmann K.A. Submitted (MAR-2002) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
[7]	"SOS4, a pyridoxal kinase gene, is required for root hair development in Arabidopsis." Shi H., Zhu J.-K. Plant Physiol. 129:585-593(2002) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF404865 mRNA. Translation: AAL57364.2. AF400125 Genomic DNA. Translation: AAK94020.1. AF400125 Genomic DNA. Translation: AAK94021.1. AB012241 Genomic DNA. Translation: BAB09031.1. CP002688 Genomic DNA. Translation: AED94239.1. CP002688 Genomic DNA. Translation: AED94240.1. AY136333 mRNA. Translation: AAM96999.1. BT008815 mRNA. Translation: AAP68254.1. AY084419 mRNA. Translation: AAM60993.1.
IPI	IPI00544571. IPI00548417.
RefSeq	NP_001078677.1. NM_001085208.1. NP_198601.2. NM_123144.3.
UniGene	At.28304.
3D structure databases
ProteinModelPortal	Q8W1X2.
SMR	Q8W1X2. Positions 17-305.
ModBase	Search...
Proteomic databases
PaxDb	Q8W1X2.
PRIDE	Q8W1X2.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
EnsemblPlants	AT5G37850.2; AT5G37850.2; AT5G37850.
GeneID	833763.
KEGG	ath:AT5G37850.
Organism-specific databases
TAIR	At5g37850.
Phylogenomic databases
eggNOG	COG2240.
HOGENOM	HOG000258174.
InParanoid	Q8W1X2.
KO	K00868.
OMA	IQSHTVQ.
PhylomeDB	Q8W1X2.
ProtClustDB	PLN02978.
Enzyme and pathway databases
UniPathway	UPA00190; UER00298.
Gene expression databases
ArrayExpress	Q8W1X2.
Genevestigator	Q8W1X2.
GermOnline	AT5G37850. Arabidopsis thaliana.
Family and domain databases
InterPro	IPR013749. HMP-P_kinase-1. IPR004625. PyrdxlP_synth_PyrdxlKinase. [Graphical view]
PANTHER	PTHR10534. PTHR10534. 1 hit.
Pfam	PF08543. Phos_pyr_kin. 1 hit. [Graphical view]
TIGRFAMs	TIGR00687. pyridox_kin. 1 hit.
ProtoNet	Search...

Entry information

Entry name

PDXK_ARATH

Accession

Primary (citable) accession number: Q8W1X2
Secondary accession number(s): Q94EN4, Q9FKE1

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 6, 2002
Last sequence update:	December 6, 2002
Last modified:	May 1, 2013
This is version 92 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program