dsdA (PA3357, Q9HYN9) review notes

No deep-research provider was available. Literature checked by hand on 2026-11-05: cached
PMID:26957519 (abstract only; no PMC copy) and Europe PMC search '"dsdA" AND aeruginosa'. The
other hits concern E. coli, Proteus or P. putida; PMID:26957519 is the only PAO1 study.

Function

PLP-dependent D-serine dehydratase (D-serine ammonia-lyase, EC 4.3.1.18) of the
serine/threonine dehydratase family, DsdA subfamily (HAMAP MF_01030). The PLP lysine is K119
(HAMAP).
Activity and substrate range PMID:26957519.
Physiology: the gene is cryptic. PAO1 uses D-serine through DadA, and dsdA supports growth
only when supplied on a plasmid [PMID:26957519 "Growth on D-serine as the sole source of
nitrogen was retained in the ∆dsdA mutant and was abolished completely in the ∆dadA and
∆dadA-∆dsdA mutants."; "However, when complemented by dsdA on a plasmid, the double mutant
was able to grow on D-serine as the sole source of carbon and nitrogen, supporting the
proposed biochemical function of DsdA in the conversion of D-serine into pyruvate and
ammonia."].

PseudoCAP IBA-seed assessment

Seeds from .cache/paint/IBD.gaf; other seeds' rows from QuickGO, 2026-11-05.

PTN node	node term	n_seeds	leaf IBAs	seed annotation (term, evidence, PMID)	verdict	rationale	other seeds	IBD stands without this seed?
PTN000034699	GO:0008721 D-serine ammonia-lyase activity	2	7 (7 taxa)	GO:0008721, IDA, PMID:26957519 (PseudoCAP)	SOUND	The abstract states a substrate screen and a Km for D-serine (330 μM), so the activity was assayed on DsdA itself.	E. coli DsdA P00926 (IDA PMID:5327100, PMID:5327101; EcoliWiki, CACAO, EcoCyc)	Yes

The node term is the exact reaction and suits a small DsdA clade (7 leaves). The node also
carries NOT annotations for L-serine/L-threonine dehydratase activities, consistent with the
D-specificity reported here. No PSEUDOCAP or GO_CENTRAL defect.

Other rows:
- GO:0036088 D-serine catabolic process (IBA, IEA): accepted. DsdA converts D-serine to
pyruvate and ammonia when it is expressed, although the chromosomal gene is cryptic in
PAO1 and DadA does this job under laboratory conditions.
- GO:0016836 hydro-lyase activity (UniRule IEA): the overall reaction is classed as an
ammonia-lyase (EC 4.3.1.18; GO:0008721 is_a carbon-nitrogen lyase), not a C-O hydro-lyase.
MODIFY to GO:0008721.