title: Solution structure of stem-loop alpha of the hepatitis B virus post-transcriptional regulatory element.
abstract: Chronic hepatitis B virus (HBV) infections may lead to severe diseases like liver cirrhosis or hepatocellular carcinoma (HCC). The HBV post-transcriptional regulatory element (HPRE) facilitates the nuclear export of unspliced viral mRNAs, contains a splicing regulatory element and resides in the 3'-region of all viral transcripts. The HPRE consists of three sub-elements alpha (nucleotides 1151-1346), beta1 (nucleotides 1347-1457) and beta2 (nucleotides 1458-1582), which confer together full export competence. Here, we present the NMR solution structure (pdb 2JYM) of the stem-loop alpha (SLalpha, nucleotides 1292-1321) located in the sub-element alpha. The SLalpha contains a CAGGC pentaloop highly conserved in hepatoviruses, which essentially adopts a CUNG-like tetraloop conformation. Furthermore, the SLalpha harbours a single bulged G residue flanked by A-helical regions. The structure is highly suggestive of serving two functions in the context of export of unspliced viral RNA: binding sterile alpha motif (SAM-) domain containing proteins and/or preventing the utilization of a 3'-splice site contained within SLalpha.
authors.affiliation: Leibniz-Institut für Altersforschung/Fritz-Lipmann-Institut, Beutenbergstr. 11, D-07745 Jena, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schwalbe
authors.forename: Oliver
authors.initials: O
authors.lastname: Ohlenschläger
authors.forename: Aliaksandr
authors.initials: A
authors.lastname: Marchanka
authors.forename: Ramadurai
authors.initials: R
authors.lastname: Ramachandran
authors.forename: Sabine
authors.initials: S
authors.lastname: Häfner
authors.forename: Tilman
authors.initials: T
authors.lastname: Heise
authors.forename: Matthias
authors.initials: M
authors.lastname: Görlach
mesh_terms: D006515:Hepatitis B virus / Q000235:genetics*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D034443:RNA Transport; D012367:RNA, Viral / Q000737:chemistry* / Q000378:metabolism; D038621:Regulatory Sequences, Ribonucleic Acid; D012996:Solutions
chemical_list: D012367:RNA, Viral; D038621:Regulatory Sequences, Ribonucleic Acid; D012996:Solutions