Table 2.

List of ten GH126 proteins possessing either the N- or C-terminal extension

No.a	Organism	GenBankb	Length	Extensionc	GH126d	Motife	Template (PDB)f	CDDg	Pfamh
1	Bacillus velezensis	QHK13041.1	637	458–636	43–353	GGDEF	Signalling protein from Caulobacter vibrioides (1W25)	+  +	+  +
2	Clostridium butyricum	QJU43754.1	521	36–202	207–520	Trx-like	Protein DipZ from Mycobacterium tuberculosis (2HYX)	+  +	+  +
3	Clostridium butyricum	APF21752.1	521	53–197	199–520	Trx-like	Protein DipZ from Mycobacterium tuberculosis (2HYX)	+  +	+  +
4	Clostridium butyricum	AXB84457.1	526	41–207	212–525	Trx-like	Protein DipZ from Mycobacterium tuberculosis (2HYX)	+  +	+  +
5	Heliorestis convoluta	QGG46501.1	523	~ 1–150	166–520	---	No relevant homologous structure found	+  +	DUF
6	Lactobacillus bifermentans	QGG60425.1	776	178–294	450–774	LRR	Internalin k from Listeria monocytogenes (4L3A)	---	+
7	Lactobacillus brevis	AYM02277.1	1399	37–759	1051–1390	LRR	Ser/Thr-protein kinase from Arabidopsis thaliana (6S6Q)	+  +	+  +
8	Lactobacillus paraplantarum	ALO03904.1	658	47–151	317–658	LRR	Internalin k from Listeria monocytogenes (4L3A)	---	+
9	Lactobacillus sp. CBA3606	AVK64614.1	658	47–151	322–658	LRR	Internalin k from Listeria monocytogenes (4L3A)	+	---
10	Bacteroides xylanolyticus	WP_104434259.1	538	36–209	213–532	Trx-like	Protein DipZ from Mycobacterium tuberculosis (2HYX)	+  +	+  +

^aProteins Nos 1–9 were taken directly from the CAZy database from the family GH126; they all originate from the phylum Firmicutes. The protein No. 1 should belong to the group of the PssZ protein from L. monocytogenes, whereas the proteins Nos 2–9 should belong to the group of the CPF_2247 amylolytic enzyme from C. perfringens (for details, see Kerenyiova and Janecek 2020). Note, the protein No. 5 from Heliorestis convoluta exhibits features of both above-mentioned groups. The protein No. 10 was caught by the BLAST search (cf. Table 1)

^bThe accession numbers from the GenBank database

^cThe borders of individual extensions were decided with respect to: (1) sequence alignment with family GH126 members without any extension (mainly the two members with solved tertiary structure—CPF_2247 and PssZ); and (2) structure homology modelling results obtained by the Phyre2 server

^dThe approximate borders of the family GH126 (α/α)₆-barrel anticipated from the results provided by the Phyre2 server according to the templates of the CPF_2247 amylolytic enzyme (3REN)

^eThe motifs are abbreviated as follows: GGDEF, a diguanylate cyclase domain with the GGDEF region; Trx-like, thioredoxin-like fold; LRR, leucine-rich repeat

^fA protein used as one of a few closely related best structural templates for homology modelling by the Phyre2 server (PDB code in parentheses)

^g,hA search in databases CDD and Pfam using the entire amino acid sequence. The sign “ +  + ” means the results from homology modelling were confirmed. The results were confirmed also for the sign “ + ”; in that case just the first 300 residues from the N-terminal end were used for the particular search. For the protein No. 5: DUF—an archaeal domain of unknown function DUF373 (predicted to be an integral membrane protein with six transmembrane regions)—although shown here, considered irrelevant since spanning only a short region of residues 42–83