Single-stranded DNA-binding protein that preferentially binds to the sterol regulatory element (SRE) sequence 5'-GTGCGGTG-3', and thereby mediates transcriptional repression (By similarity). Has a role as transactivator of the Myc promoter (By similarity). Binds single-stranded RNA in a sequence-specific manner (By similarity). Binds G-rich elements in target mRNA coding sequences (By similarity). Prevents G-quadruplex structure formation in vitro, suggesting a role in supporting translation by resolving stable structures on mRNAs (By similarity). Associates with the 40S ribosomal subunit, the 80S ribosome and with polysomes. Arginine methylation by PRMT1 in the Arg/Gly-rich region impedes RNA binding.