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 (PubMed:12706888). 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. Expressed from pre-gastrulation to organogenesis stages (at protein level) (PubMed:12706888). At this stage 7.5 dpc, expression becomes asymmetrical and localizes to all three germ layer regions of the anterior conceptus, suggesting a possible role in anterior-posterior axis patterning (at protein level) (PubMed:12706888). Later expressed in the forebrain (9 dpc and 10 dpc) and in the midbrain (11.5 dpc) (at protein level) (PubMed:12706888). From 9 dpc to 11.5 dpc, expressed in the early craniofacial structures, limb buds and somites (at protein level) (PubMed:12706888). Highest expression is in the face and includes the cranial and caudal regions of the mandibular prominences, the budding maxillary prominences and the roof of the stomodeum (at protein level) (PubMed:12706888). Before gastrulation, 5.5 dpc, expression is initially symmetric and uniform in the epiblast and in the extra-embryonic visceral endoderm (PubMed:7896269). Arginine methylation by PRMT1 in the Arg/Gly-rich region impedes RNA binding.