pilT (PA0395, P24559) notes

Identity

UniProt P24559 (PILT_PSEAE), reviewed, 344 aa; type IV pilus retraction
ATPase. GspE/secretion NTPase superfamily (Pfam PF00437 T2SSE; InterPro
IPR006321 PilT/PilU); PANTHER PTHR30486:SF6. Structures 3JVU/3JVV.

Purified PilT is an ATPase; Walker A/B mutants abolish twitching; Asp Box
and His Box residues needed for ATPase activity [PMID:18174131 "Assay of
purified 6xHis-tagged PilB, PilT and PilU from P. aeruginosa showed that all
three proteins have ATPase activities in vitro."; "mutation of these
residues caused loss of PilT ATPase activity in vitro"]. PilT powers
retraction PMID:18174131. This is the PilB/PilT/PilU ATPase paper also used in
genes/PSEAE/pilB and genes/PSEAE/pilU.
Hexameric retraction motor, crystal structures with and without AMP-PCP
[PMID:20595000 "Retraction is accomplished by the motor protein PilT.";
"revealing an interlocking hexamer"]. Glu204 (Walker B) assigned to
catalysis PMID:20595000.
Cytoplasmic, bipolar localisation of functional YFP fusions
PMID:15659660.
UniProt disruption phenotype: "Mutants retain surface pili but have lost
twitching motility".

GO:0044096 type IV pilus is the extracellular fibre. PilT is a soluble
cytoplasmic hexamer that docks on the base of the machine; it is not part of
the fibre. The PseudoCAP TAS located_in type IV pilus from the structure
paper conflates the machine with the fibre (same pattern as the
pilM/N/O/P IMP rows). Not an IBD seed.
GO:0043108 pilus retraction: no type IV-specific child exists, so this is
as precise as GO allows.

IBDs: GO:0016887 ATP hydrolysis activity (seed UniProtKB:P24559, PseudoCAP
IDA PMID:18174131) and GO:0005829 cytosol (seed E. coli YggR, P52052),
both 2024-08-27.
Leaves (8, 8 taxa): P. aeruginosa PilT, Xanthomonas PilT (Q7CLR1),
Shewanella PilT (Q8EBZ4), Vibrio VC_0462 (Q9KUQ3), E. coli YggR (P52052),
Salmonella YggR (Q8ZM48), Yersinia YPO0940, Coxiella DotB (Q83B70). All
PilT-like secretion NTPases with Walker A/B, Asp Box and His Box motifs;
ATP hydrolysis is a safe, appropriately general term across this clade
(DotB of the Dot/Icm T4SS is also an ATPase).

PTN node	node term	n_seeds	leaf IBAs	seed annotation (term, evidence, PMID)	verdict	rationale
PTN002020799	GO:0016887 ATP hydrolysis activity	1 (sole)	8 (8 taxa)	GO:0016887 ATP hydrolysis activity, IDA, PMID:18174131 (PseudoCAP)	SOUND	In vitro ATPase assay of purified P. aeruginosa PilT, stated in the abstract, with catalytic-residue mutants that abolish activity. The secretion-NTPase catalytic motifs are conserved across the node (PilT, YggR, DotB), so ATP hydrolysis is a suitably broad node term.

ACCEPT: ATP binding (IEA); cytoplasm (EXP, IEA); cytosol (IBA); ATP
hydrolysis (IBA, IDA); motility (TAS); pilus retraction (TAS).
REMOVE: located_in type IV pilus (TAS, PseudoCAP), with PSEUDOCAP defect.