Reviewed, UniProtKB/Swiss-Prot P27725 (AK1H_SERMA)

Names and origin

Protein names

Recommended name:
    Bifunctional aspartokinase/homoserine dehydrogenase 1
Alternative name(s):
    Aspartokinase I/homoserine dehydrogenase I
      Short name=AKI-HDI
Including the following 2 domains:
    1- Recommended name:
            Aspartokinase
              EC=2.7.2.4
    2- Recommended name:
            Homoserine dehydrogenase
              EC=1.1.1.3

Gene names

Name:	thrA
Synonyms:	thrA1, thrA2

Organism

Serratia marcescens

Taxonomic identifier

615 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Serratia

Protein attributes

Sequence length	819 AA.
Sequence status	Complete.
Protein existence	Inferred from homology.

General annotation (Comments)

Catalytic activity	L-homoserine + NAD(P)+ = L-aspartate 4-semialdehyde + NAD(P)H. ATP + L-aspartate = ADP + 4-phospho-L-aspartate.
Enzyme regulation	The enzyme activities are regulated allosterically by L-threonine.
Pathway	Amino-acid biosynthesis; L-lysine biosynthesis via DAP pathway; (S)-tetrahydrodipicolinate from L-aspartate: step 1/4. Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; L-homoserine from L-aspartate: step 1/3. Amino-acid biosynthesis; L-methionine biosynthesis via de novo pathway; L-homoserine from L-aspartate: step 3/3. Amino-acid biosynthesis; L-threonine biosynthesis; L-threonine from L-aspartate: step 1/5. Amino-acid biosynthesis; L-threonine biosynthesis; L-threonine from L-aspartate: step 3/5.
Subunit structure	Homotetramer.
Sequence similarities	In the N-terminal section; belongs to the aspartokinase family. In the C-terminal section; belongs to the homoserine dehydrogenase family. Contains 2 ACT domains.

Ontologies

Keywords
Biological process	Amino-acid biosynthesis Threonine biosynthesis
Domain	Repeat
Ligand	ATP-binding NADP Nucleotide-binding
Molecular function	Kinase Oxidoreductase Transferase
Technical term	Allosteric enzyme Multifunctional enzyme
Gene Ontology (GO)
Biological process	oxidation reduction Inferred from electronic annotation. Source: UniProtKB-KW threonine biosynthetic process Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW NADP or NADPH binding Inferred from electronic annotation. Source: InterPro amino acid binding Inferred from electronic annotation. Source: InterPro aspartate kinase activity Inferred from electronic annotation. Source: EC homoserine dehydrogenase activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 819	819	Bifunctional aspartokinase/homoserine dehydrogenase 1		PRO_0000066682
Regions
	Domain	316 – 385	70	ACT 1
	Domain	397 – 468	72	ACT 2
	Nucleotide binding	471 – 478	8	NADP Potential
	Region	1 – 249	249	Aspartokinase By similarity
	Region	250 – 470	221	Interface By similarity
	Region	471 – 819	349	Homoserine dehydrogenase By similarity
Natural variations
	Natural variant	330	1	G → D in strain: Sr41 / 8000, Sr41 / HNr21; loss of feedback inhibition.
	Natural variant	352	1	S → F in strain: Sr41 / TLr156; loss of feedback inhibition.
	Natural variant	479	1	A → T in strain: Sr41 / HNr59; Thr-resistant HDI.

Sequences

	Sequence		Length	Mass (Da)
	P27725-1 [UniParc]. Last modified August 1, 1992. Version 1. Checksum: 1F18552B036A8E39	FASTA	819	88,495
	10 20 30 40 50 60 MRVLKFGGTS VANAERFLRV ADIMESNARQ GQVATVLSAP AKITNHLVAM IDKTVAGQDI 70 80 90 100 110 120 LPNMSDAERI FADLLSGLAQ ALPGFEYDRL KGVVDQEFAQ LKQVLHGVSL LGQCPDSVNA 130 140 150 160 170 180 AIICRGEKLS IAIMEGVFRA KGYPVTVINP VEKLLAQGHY LESTVDIAES TLRIAAAAIP 190 200 210 220 230 240 ADHIVLMAGF TAGNDKGELV VLGRNGSDYS AAVLAACLRA DCCEIWTDVD GVYTCDPRTV 250 260 270 280 290 300 PDARLLKSMS YQEAMELSYF GAKVLHPRTI TPIAQFQIPC LIKNTSNPQA PGTLIGKDST 310 320 330 340 350 360 DADMPVKGIT NLNNMAMINV SGPGMKGMVG MAARVFAVMS RAGISVVLIT QSSSEYSISF 370 380 390 400 410 420 CVPQGELQRA RRALEEEFYL ELKDGVLDPL DVMERLAIIS VVGDGMRTLR GISARFFSAL 430 440 450 460 470 480 ARANINIVAI AQGSSERSIS VVVSNDSATT GVRVSHQMLF NTDQVIEVFV IGVGGVGGAL 490 500 510 520 530 540 IEQIYRQQPW LKQKHIDLRV CGIANSRVML TNVHGIALDS WRDALAGAQE PFNLGRLIRL 550 560 570 580 590 600 VKEYHLLNPV IVDCTSSQAV ADQYVDFLAD GFHVVTPNKK ANTSSMNYYQ QLRAAAAGSH 610 620 630 640 650 660 RKFLYDTNVG AGLPVIENLQ NLLNAGDELV RFSGILSGSL SFIFGKLDEG LSLSAATLQA 670 680 690 700 710 720 RANGYTEPDP RDDLSGMDVA RKLLILAREA GYKLELSDIE VEPVLPPSFD ASGDVDTFLA 730 740 750 760 770 780 RLPELDKEFA RNVANAAEQG KVLRYVGLID EGRCKVRIEA VDGNDPLYKV KNGENALAFY 790 800 810 SRYYQPLPLV LRGYGAGNDV TAAGVFADLL RTLSWKLGV

References

[1]

"Nucleotide sequence of the Serratia marcescens threonine operon and analysis of the threonine operon mutations which alter feedback inhibition of both aspartokinase I and homoserine dehydrogenase I." Omori K., Suzuki S., Komatsubara S. J. Bacteriol. 175:785-794(1993) [PubMed: 8423151] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: Sr41 / 8000, Sr41 / HNr21, Sr41 / HNr59 and Sr41 / TLr156.

Cross-references

Sequence databases
EMBL GenBank DDBJ	D10385 Genomic DNA. Translation: BAA38474.1. D10386 Genomic DNA. Translation: BAA38477.1. D10387 Genomic DNA. Translation: BAA38480.1. X60821 Genomic DNA. Translation: CAA43212.1.
PIR	B47057.
3D structure databases
SMR	P27725. Positions 2-461, 463-813.
ModBase	Search...
Enzyme and pathway databases
BRENDA	1.1.1.3. 457. 2.7.2.4. 457.
Family and domain databases
InterPro	IPR002912. ACT_bd. IPR001048. Asp/Glu/Uridylate_kinase. IPR005106. Asp/hSer_DH_NAD-bd. IPR001341. Asp_kinase_dom. IPR018042. Aspartate_kinase_CS. IPR011147. bifunc_aspartokin/hSer_DH. IPR001342. Homoserine_dehydrogenase_cat. IPR019811. Homoserine_dehydrogenase_CS. IPR016040. NAD(P)-bd_dom. [Graphical view]
Gene3D	G3DSA:3.40.1160.10. Aa_kinase. 1 hit. G3DSA:3.40.50.720. NAD(P)-bd. 1 hit.
Pfam	PF00696. AA_kinase. 1 hit. PF01842. ACT. 2 hits. PF00742. Homoserine_dh. 1 hit. PF03447. NAD_binding_3. 1 hit. [Graphical view]
PIRSF	PIRSF000727. ThrA. 1 hit.
TIGRFAMs	TIGR00657. asp_kinases. 1 hit.
PROSITE	PS00324. ASPARTOKINASE. 1 hit. PS01042. HOMOSER_DHGENASE. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

AK1H_SERMA

Accession

Primary (citable) accession number: P27725
Secondary accession number(s): Q59936 , Q59937, Q60127, Q60157

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 1, 1992
Last sequence update:	August 1, 1992
Last modified:	February 9, 2010
This is version 76 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)