LYS21/YDL131W Summary

Standard Name	LYS21
Systematic Name	YDL131W
Feature Type	ORF, Verified
Description	Homocitrate synthase isozyme; catalyzes the condensation of acetyl-CoA and alpha-ketoglutarate to form homocitrate, which is the first step in the lysine biosynthesis pathway; LYS21 has a paralog, LYS20, that arose from the whole genome duplication (1, 2 and see Summary Paragraph)
Name Description	LYSine requiring

Chromosomal Location	ChrIV:227393 to 228715 \| ORF Map \| GBrowse

Gene Ontology Annotations All LYS21 GO evidence and references

	View Computational GO annotations for LYS21
Molecular Function
Manually curated	homocitrate synthase activity (ISS)
Biological Process
Manually curated	lysine biosynthetic process via aminoadipic acid (IGI, IMP)
Cellular Component
Manually curated	nucleus (IDA)
High-throughput	nucleus (IDA)

Pathways	lysine biosynthesis

Mutant phenotypes All LYS21 Phenotype evidence and references

Classical genetics
null	auxotrophy
Large-scale survey
null	competitive fitness: decreased haploinsufficient resistance to streptomycin: decreased resistance to cycloheximide: decreased viable
Resources	PROPHECY \| SCMD \| ScreenTroll \| Yeast Fitness Database

interactions All LYS21 Interaction evidence and references

	54 total interaction(s) for 44 unique genes/features.
Physical Interactions	Affinity Capture-MS: 15 Affinity Capture-RNA: 1 Biochemical Activity: 4 PCA: 4 Protein-peptide: 4 Two-hybrid: 1
Genetic Interactions	Dosage Rescue: 1 Negative Genetic: 15 Phenotypic Enhancement: 1 Phenotypic Suppression: 1 Positive Genetic: 2 Synthetic Growth Defect: 2 Synthetic Lethality: 2 Synthetic Rescue: 1
Resources	BioGRID \| BOND \| BioPIXIE \| CYC2008 (complexes) \| Complexome \| DIP \| DRYGIN \| GeneMANIA \| InterologFinder

Expression Summary


Resources	Expression Summary \| Cell cycle and metabolic oscillation \| Cell cycle transcript profile \| Cyclebase \| Genevestigator \| GermOnline \| SPELL \| YMGV \| YeastFunc

Protein Information All LYS21 Protein evidence and references

Localization	YeastRC \| Organelle DB (UMich) \| YPL+ \| YeastGFP
Phosphorylation	PhosphoGRID \| PhosphoPep Database
Structure	GPMDB \| SCOP \| YeastRC
Homologs	Ashbya (AGD) \| AspGD Homologs \| CGD Homologs \| Fungal Orthogroups Repository \| P-POD \| PDB Homologs \| PhylomeDB \| YGOB \| YOGY

sequence information

ChrIV:227393 to 228715 | |

Last Update

Coordinates: 1996-07-31 | Sequence: 1996-07-31

Subfeature details

	Relative Coordinates	Chromosomal Coordinates	Most Recent Updates
	Relative Coordinates	Chromosomal Coordinates	Coordinates	Sequence
CDS	1..1323	227393..228715	1996-07-31	1996-07-31

Retrieve sequences

Analyze Sequence

S288C only	BLASTP \| ATCC/WashU Clones \| BLASTN \| Design Primers \| Restriction Fragment Map \| Restriction Fragment Sizes \| Six-Frame Translation
S288C vs. other species	Fungal Alignment \| BLASTN vs. fungi \| BLASTP at NCBI \| BLASTP vs. fungi \| Synteny Viewer
S288C vs. other strains	Strain Alignment

Resources

External Links	All Associated Seq \| E.C. \| Entrez Gene \| Entrez RefSeq Protein \| MIPS \| Search all NCBI (Entrez) \| UniProtKB

Primary SGDID	S000002289

SUMMARY PARAGRAPH for LYS21

About lysine biosynthesis

S. cerevisiae synthesizes the essential amino acid L-lysine via the L-alpha-aminoadipic acid pathway instead of the diaminopmelate pathway (3). Originally proposed to be characteristic of fungi, recent studies suggest prokaryotes also synthesize lysine via the alpha-aminoadipic acid pathway (4). Intermediates in this pathway are often incorporated into secondary metabolites. For example, it has been well- studied that alpha-aminoadipate is required for penicillin production (3). Regulation of the lysine biosynthetic pathway in S. cerevisiae is an interaction between general amino acid control (via Gcn4p) (5), feedback inhibition of homocitrate synthase activity by lysine (6), and induction of Lys14p by alpha-aminoadipate semialdehyde (7).

Last updated: 2007-10-04

References cited on this page View Complete Literature Guide for LYS21

1)	Ramos F, et al. (1996) Identification of a gene encoding a homocitrate synthase isoenzyme of Saccharomyces cerevisiae. Yeast 12(13):1315-20
2)	Byrne KP and Wolfe KH (2005) The Yeast Gene Order Browser: combining curated homology and syntenic context reveals gene fate in polyploid species. Genome Res 15(10):1456-61
3)	Zabriskie TM and Jackson MD (2000) Lysine biosynthesis and metabolism in fungi. Nat Prod Rep 17(1):85-97
4)	Nishida H and Nishiyama M (2000) What is characteristic of fungal lysine synthesis through the alpha-aminoadipate pathway? J Mol Evol 51(3):299-302
5)	Hinnebusch A (1992) "General and Pathway-specific Regulatory Mechanisms Controlling the Synthesis of Amino Acid Biosynthetic Enzymes in Saccharomyces cerevisiae". Pp. 319-414 in The Molecular and Cellular Biology of the Yeast Saccharomyces: Gene Expression, edited by Jones EW, Pringle JR and Broach JR. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press
6)	Feller A, et al. (1999) In Saccharomyces cerevisae, feedback inhibition of homocitrate synthase isoenzymes by lysine modulates the activation of LYS gene expression by Lys14p. Eur J Biochem 261(1):163-70
7)	El Alami M, et al. (2000) Characterisation of a tripartite nuclear localisation sequence in the regulatory protein Lys14 of Saccharomyces cerevisiae. Curr Genet 38(2):78-86