Table 1.

Sequence architecture of four human mannosyltransferases PIG-M, PIG-V, PIG-B, PIG-Z as well as PIG-U and PIG-W.

Protein	Sequence length (AAs)	Total number of TMs	TMs involved in domain BindGPILA	Conserved catalytic motif between 1st and 2nd TM in the domain	Best Pfam Domain hit
PIGM_HUMAN (Q9H3S5)	423	10	1–10	DxD	Mannosyl_trans (PF05007) E-value = 4.0e-109
PIGV_HUMAN (Q9NUD9)	493	10	1–10	D/ExE	Mannosyl_trans2 (PF04188) E-value = 4.0e-216
PIGB_HUMAN (Q92521)	554	11	1–10	DE	Glyco_transf_22 (PF03901) E-value = 6.0e-123
PIGZ_HUMAN (Q86VD9)	579	11	1–10	DE	Glyco_transf_22 (PF03901) E-value = 6.4e-52
PIGU_HUMAN (Q9H490)	435	10	1–10	–	PIG-U (PF06728) E-value = 6.0e-115
PIGW_HUMAN (Q7Z7B1)	504	13	2–11	–	GWT1 (PF06423) E-value = 1.2e-35

For each of the six human proteins each representing an orthologous protein family, total sequence lengths, total number of TMs and the range of TMs within the newly discovered membrane-embedded domain BindGPILA are listed. We also provide the conserved catalytically relevant motif in the luminal loop between the 1st and the 2nd TMs within the domain. Further, we list the best Pfam hit found with a plain HMMER search. To note, we provide a full list of hits from searches with sequences of one orthologous family into any of the other 5 families with HHPRED or dissectHMMER in Suplementary Table S1.