MYRbase: analysis of genome-wide glycine myristoylation enlarges the functional spectrum of eukaryotic myristoylated proteins

Table 3 The five classes of co-occurring membrane attachment factors (coMAFs)

coMAF class*	I	II	III	IV	V
	Palmitoylatable cysteine^†	Amino-terminal cluster of positive charges^‡	PIP₂-specific binding domain^§	Transmembrane segments^¶	Other/not attributable (for example, protein-protein interactions)^¥
Experimentally verified + homolog	453	443/133/12	9	0	432
Additional NEW prediction	728	729/269/58	21	203	1,860

*Distribution of the five classes of coMAFs among the set of experimentally verified myristoylated proteins plus their homologs and the set of additional new predictions. Assignments are not necessarily unique, but can be combinations thereof. ^†At least one palmitoylatable cysteine within the first five residues (starting with the myristoylated glycine). ^‡The content of positive charges (amino acids lysine (K), arginine (R) and histidine (H)) in the region of positions 6 to 35 is compared to the average composition in GenBank in the same region. The values correspond to hits occurring using threshold deviations of 1, 2 and 3σ from the GenBank average. ^§Significant HMMER-hit (below E-value of 0.01) with phosphatidylinositol-bisphosphate (PIP₂)-specific binding domains (PH, ENTH, FERM, PX or FYVE). ^¶A very conservative method was used to detect putative transmembrane segments. Besides requiring the attribute 'trusted' by the sensitive method DAS-TMfilter [151], we only list the hits that have more than three predicted TM regions and that are additionally filtered for their overall polarity measured by the content of positive charges. ^¥All other proteins that did not fulfill any of the above criteria.

ISSN: 1474-760X