histone-fold domain found in nuclear transcription factor Y subunit gamma (NF-YC) and similar proteins
NF-YC, also called CAAT box DNA-binding protein subunit C, or nuclear transcription factor Y subunit C, or transactivator HSM-1/2, is a component of the sequence-specific heterotrimeric transcription factor (NF-Y) which specifically recognizes a 5'-CCAAT-3' box motif found in the promoters of its target genes. NF-Y can function as both an activator and a repressor, depending on its interacting cofactors. NF-Y is a heterotrimeric transcription factor composed of three components, NF-YA, NF-YB and NF-YC. NF-YB and NF-YC must interact and dimerize for NF-YA association and DNA binding. The family also includes NF-YC homologs such as Aspergillus fumigatus CCAAT-binding complex (CBC) subunit HapE and Saccharomyces cerevisiae transcriptional activator Hap5. HapE is a component of CBC, which is composed of the histone-like subunits HapC and HapE as well as the DNA specificity conferring subunit HapB. In yeast, Hap5 is a component of the CCAT-binding factor (CBF or HAP complex II), which is a transcriptional activator and binds to the upstream activation site (UAS2) of the CYC1 gene and other genes involved in mitochondrial electron transport and activates their expression. It recognizes the sequence 5'-CCAAT-3'. Hap5 is essential for DNA-binding activity.
Jiyao W et al.(2023). "The conserved domain database in 2023.",