SEQUENCE-ANALYSIS AND COMPOSITIONAL PROPERTIES OF UNTRANSLATED REGIONS OF HUMAN MESSENGER-RNAS

A detailed computer analysis of the untranslated regions, 5'-UTR and 3 '-UTR, of human mRNA sequences is reported. The compositional properti es of these regions, compared with those of the corresponding coding r egions, indicate that 5'- U TR and 3'- U TR are less affected by the i sochore compartmentalization than the corresponding third codon positi ons of mRNAs. The presence of higher functional constraints in 5'-UTR is also reported. Dinucleotide analysis shows a depletion of CpG and T pA in both sequences. A search for significant sequence motifs using t he WORDUP algorithm reveals the patterns already known to have a funct ional role in the mRNA UTR, and several other motifs whose functional roles remain to be demonstrated. This type of analysis may be particul arly useful for guiding site-directed mutagenesis experiments. In addi tion, it can be used for assessing the nature of anonymous sequences n ow produced in large amounts in megabase sequencing projects.