Mutations in XPA, particularly in the DNA-binding domain, are associated with severe XP clinical phenotypes.
XPA coordinates recruitment and assembly of the enzymes that repair the damaged DNA, and mutations in its DNA-binding domain are associated with the most severe clinical XP phenotypes.
The SR-25-like domain is associated with RNA-binding modules, RNA recognition motif (RRM) [ 26] and PRP38 [ 36], It is also distantly related to SR-25 domain which may be involved in RNA splicing, as revealed by the SCOOP program [ 37].
As it was originally defined, the G-patch domain is associated with nucleic acids binding domains.
In contrast, the YABBY domain is associated with non-specific DNA-binding [ 5].
Transcription regulatory domain is associated with response regulator receiver domain and plays an important role in DNA-binding and regulation of transcription [ 46, 47].
However, point mutations affecting the substrate-binding sequence motifs of the McyA2 adenylation domain were associated with the change in substrate specificity in two strains of Microcystis.
The NAD-binding-8 domain is involved in coenzyme binding [ 34], whereas the proteins containing TAXi domains are associated with proteolysis of phytopathogen xylanase secreted by the pathogen to degrade plant cell wall during plant pathogen infection [ 35].
However, assessment of H3K27me3 domains showed that only a small minority (∼3%) of REST-bound sites were associated with significant enrichment of H3K27me3 relative to input, and only 0.5% of H3K27me3-enriched domains were associated with REST binding.
Several further domains were associated with transcriptional factors integrated with signalling pathways, that is, homeobox domain, helix-loop-helix, or ligand-binding domain of nuclear hormone receptor.
