Table I.

Sequence-based classifiers of plant PLCP subfamilies

Subfamily	Classifiers
RD21A-like	C-terminal granulin domain
CEP1-like	{K/H}DEL ER-retrieval signal at the C terminus
XCP2-like	Carries a conserved PGS in the TGNL{S/T} motif in the protease domain
XBCP3-like	C-terminal granulin domain
THI1-like	No distinct features noted
SAG12-like	Carries an extra Cys before the catalytic Cys (CGCCWAFS motif)
RD19A-like	ERFNAQ instead of ERFNIN in the prodomain; two extra disulfide bridges in the protease domain (4 and 5); conserved PGS in the VxNF{S/T} motif in the middle of the protease domain
AALP-like	NPIR vacuolar targeting signal at the N terminus of the prodomain; extra Cys in the ATC motif in the C terminus of the protease domain; extra Cys in the CSAT motif at the C terminus of the prodomain; conserved PGS in the VNIT motif in the middle of the protease domain
CTB3-like	No ERFNIN/ERFNAQ motif in the prodomain; no disulfide bridge 3: unpaired Cys in the ECGIE motif in the C terminus; four extra disulfide bridges (6–9); PGS located in the nonconserved loop between disulfide bridges 6 and 2