msrA (PA5018, Q9HUF1) review notes

Peptide methionine (S)-sulfoxide reductase MsrA (HAMAP MF_01401, PMSR Pfam).

Literature (no deep-research provider available; own reading)

Romsang et al. 2013 (full text cached, PMC3719549): msrA is constitutively and
highly expressed; msrB is oxidant-inducible. msrA mutants are less resistant to
NaOCl and H2O2 PMID:23687271, and plasmid msrA fully
complements PMID:23687271. msrA mutants are paradoxically more
paraquat resistant, and msrA/msrB mutants are attenuated in a Drosophila model.
The paper does not assay Msr enzyme activity; the MF rows rest on family
(IBA/IEA) inference, which is strong for MsrA.
Comparator for the BP: MsrA repairs oxidised Met residues itself, so it does
some of the work of the oxidative-stress response (not only required for it).
Other seeds at the same node carry the same term by IMP (yeast MXR1, S. pombe
mxr1, Arabidopsis MSRA2/MSR4, A. nidulans).
PubMed MCP search returned API errors on 2026-11-05.

Seed support queried live in QuickGO on 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?
PTN000019085	GO:0034599 cellular response to oxidative stress	7	289 (116 taxa)	GO:0034599, IMP, PMID:23687271 (PseudoCAP)	SOUND	Full text read: deletion reduces NaOCl and H2O2 resistance and is complemented; MsrA directly repairs oxidised proteins, so this is participation, not an indirect phenotype.	S. cerevisiae MXR1 P40029 (IMP/IGI), S. pombe mxr1 Q09859 (IMP), Arabidopsis MSRA2 Q9LY15 (IMP) and MSR4 P54150 (IMP/IEP), A. nidulans C8V8B9 (IMP), Drosophila MsrA P08761 (IEP)	Yes; five independent IMP seeds across fungi and plants

No PSEUDOCAP or GO_CENTRAL defect. The node is the MsrA family; the term suits it.