Hepatitis C Virus IRES RNA-Induced Changes in the Conformation of the 40S Ribosomal Subunit

Science  09 Mar 2001:
Vol. 291, Issue 5510, pp. 1959-1962
DOI: 10.1126/science.1058409

You are currently viewing the abstract.

View Full Text

Via your Institution

Log in through your institution

Log in through your institution


Initiation of protein synthesis in eukaryotes requires recruitment of the 40S ribosomal subunit to the messenger RNA (mRNA). In most cases, this depends on recognition of a modified nucleotide cap on the 5′ end of the mRNA. However, an alternate pathway uses a structured RNA element in the 5′ untranslated region of the messenger or viral RNA called an internal ribosomal entry site (IRES). Here, we present a cryo-electron microscopy map of the hepatitis C virus (HCV) IRES bound to the 40S ribosomal subunit at about 20 Å resolution. IRES binding induces a pronounced conformational change in the 40S subunit and closes the mRNA binding cleft, suggesting a mechanism for IRES-mediated positioning of mRNA in the ribosomal decoding center.

  • * These authors contributed equally to this work.

  • Present address: Department of Biochemistry, University of Texas, Health Science Center, Houston, TX 77030, USA.

  • To whom correspondence should be addressed. E-mail: doudna{at} and joachim{at}

View Full Text

Cited By...