IRES elements:: features of the RNA structure contributing to their activity

The activity of internal ribosome entry site (IRES) elements depends on their structural organization. We have addressed here the study of conserved structural motifs in the foot-and-mouth disease virus (FMDV) IRES as an example to understand the relationship between RNA structure and function. The features of the RNA structure known to be functionally relevant are discussed in regards to the capacity to modulate interaction of translation initiation factors with the FMDV IRES element. Additionally, the contribution of non-canonical RNA-binding proteins to FMDV IRES organization as well as stimulation of its activity by other mRNA regions is discussed. (C) 2002 Societe francaise de biochimie et biologic moleculaire / Editions scientifiques et medicales Elsevier SAS. All rights reserved.