Chromatin reader component of the transcription regulatory histone acetylation (HAT) complex SAGA (PubMed:21642955, PubMed:26401015). Sgf29 specifically recognizes and binds methylated 'Lys-4' of histone H3 (H3K4me), with a preference for trimethylated form (H3K4me3) (PubMed:26401015). In the SAGA complex, sgf29 is required to facilitate crosstalk between gcn5 acetyltransferase activity and H3K4me3 recognition (PubMed:26401015). At the promoters, SAGA is required for recruitment of the basal transcription machinery (PubMed:19056896). It influences RNA polymerase II transcriptional activity through different activities such as TBP interaction and promoter selectivity, interaction with transcription activators, and chromatin modification through histone acetylation and deubiquitination (PubMed:19056896). SAGA acetylates nucleosomal histone H3 to some extent (to form H3K9ac, H3K14ac, H3K18ac and H3K23ac) (PubMed:19056896). Component of the SAGA complex. The SGF29 C-terminal (also named tudor-like) domain mediates binding to methylated 'Lys-4' of histone H3 (H3K4me). Belongs to the SGF29 family.