Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005886 plasma membrane	IEA GO_REF:0000044	ACCEPT	Summary: AlgI is a multi-pass bacterial inner-membrane protein. Reason: The reviewed topology and membrane-bound acyltransferase-family assignment support this location. Supporting Evidence: file:PSEPK/algI/algI-uniprot.txt SUBCELLULAR LOCATION: Cell inner membrane
GO:0016746 acyltransferase activity	IEA GO_REF:0000120	ACCEPT	Summary: AlgI is the membrane-bound acyl-transfer component of the alginate O-acetylation complex. Reason: The exact donor and transient acceptor remain unresolved, so this broad valid term is preferable to assigning serine O-acetyltransferase or a fabricated substrate-specific activity. Supporting Evidence: file:PSEPK/algI/algI-uniprot.txt Belongs to the membrane-bound acyltransferase family
GO:0042121 alginic acid biosynthetic process	IEA GO_REF:0000120	KEEP AS NON CORE	Summary: AlgI acts in post-polymerization alginate maturation rather than polymer formation itself. Reason: GO:0051979 is not an ontology descendant of GO:0042121, so replacing this row would lose its broader alginate-pathway context. The broad process is retained as non-core while the exact acetylation process is added separately; P. aeruginosa genetics show that algIJF are not required to synthesize the unacetylated polymer. Supporting Evidence: PMID:8636017 This indicated that the algIJF gene products were not required for polymer biosynthesis.
GO:0051979 alginic acid acetylation	ISS PMID:12003941 Mutant analysis and cellular localization of the AlgI, AlgJ,...	NEW	Summary: AlgI is required for transfer of acetyl groups into the alginate O-acetylation machinery. Reason: Isogenic P. aeruginosa algI deletion and complementation establish the ortholog role, and Q88ND2 retains the exact AlgI family, topology, and syntenic operon position. Supporting Evidence: PMID:12003941 defined nonpolar algI, algJ, and algF deletion mutants of P. aeruginosa strain FRD1 were constructed, and each mutant produced alginate lacking O-acetyl groups.

Core Functions

Multi-pass inner-membrane acyltransferase-family component that supplies acetyl groups to the periplasmic alginate O-acetylation relay.

Molecular Function:

acyltransferase activity

Directly Involved In:

alginic acid acetylation

Cellular Locations:

plasma membrane

Supporting Evidence:

PMID:12003941
each mutant produced alginate lacking O-acetyl groups.
PMID:31900562
AlgI-AlgJ-AlgF form a multiprotein complex linked via Alg8

References

Loading supporting content…

Download this section (compressed HTML)

Suggested Experiments

Experiment: Reconstitute AlgI with AlgJ and AlgF in proteoliposomes and trace transfer from isotopically labeled acetyl donors.

Type: membrane-complex reconstitution

📚 Additional Documentation

Notes

(algI-notes.md)

algI curation notes

Q88ND2 is the syntenic KT2440 AlgI ortholog and retains the exact AlgI family
and seven-pass inner-membrane architecture.
P. aeruginosa nonpolar algI deletion yields alginate lacking O-acetyl groups,
and complementation restores acetylation [PMID:12003941, "each mutant produced
alginate lacking O-acetyl groups"].
GO:0051979 is not a descendant of GO:0042121 in the current GO release.
Therefore the exact acetylation process is added separately rather than used
as a formal replacement for the broader pathway-context annotation.
The immediate acetyl donor and transient acceptor remain unresolved; retain
only the broad acyltransferase molecular function.

📄 View Raw YAML