Question

HOX family transcription factors have narrow expression patterns, which are required for normal development. Given that eukaryotic genes do not occur in operons, how can the HOXA10 transcription factor simultaneously regulate the transcription of more than 40 different target genes?

Answer 1

HOXA10 gene are present in Homo sapiens and are part of the HOX gene family and is involved in embryogenesis.The protein product of this gene is transcription factor which has the presence of homeodomain.This homeodomain is DNA binding domain with help of which it can bind to those DNA sequences which it regulates. The HOX transcription factor binds with help of homeodomain to enchancer and in thid way can simultaneously regulate the expression of many genes. As enchancer are upstream cis regulatory sequences and can regulate the gene downstream to it even it is vary far from the enchancer. Hence by binding to enchancer the HOXA10 protein controls transcription of numerous genes.