Comparative sequence analysis of the 5' noncoding region of the enteroviruses and rhinoviruses

A comparative sequence analysis of the 5' noncoding region of a subgroup of the picornaviruses, including the polioviruses, coxsackie B3, and the human rhinoviruses, reveals the conservation of certain features despite the divergence of sequence. In this subgroup, for which nine complete sequences are available, two long stretches of sequence, two pyrimidine-rich regions, and 22 hairpins are conserved. Based on these results, similar secondary structures encompassing the entire 5' noncoding regions of these viruses are predicted. The fact that sequence divergence occurred only in a manner that allowed conservation of these structures implicates a biologically functional role for this region. The possible roles it may have in the picornavirus life cycle are discussed.