1up1

UP1, THE TWO RNA-RECOGNITION MOTIF DOMAIN OF HNRNP A1UP1, THE TWO RNA-RECOGNITION MOTIF DOMAIN OF HNRNP A1

Structural highlights 1up1 is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease [ROA1_HUMAN] Amyotrophic lateral sclerosis;Inclusion body myopathy with Paget disease of bone and frontotemporal dementia. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. Function [ROA1_HUMAN] Involved in the packaging of pre-mRNA into hnRNP particles, transport of poly(A) mRNA from the nucleus to the cytoplasm and may modulate splice site selection. May play a role in HCV RNA replication. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed BACKGROUND: Heterogeneous nuclear ribonucleoprotein (hnRNP) A1 is one of the most abundant core proteins of hnRNP complexes in metazoan nuclei. It behaves as a global regulator of alternative pre-mRNA splicing by antagonizing the activities of several serine/arginine-rich splicing factors (SR proteins), resulting in the activation of distal alternative 5' splice sites and skipping of optional exons. Purified hnRNP A1 has nucleic acid annealing activity. The protein also shuttles continuously between the nucleus and the cytoplasm, a process mediated by signals within its C-terminal glycine-rich domain. The N-terminal region of human hnRNP A1, termed unwinding protein 1 (UP1), contains two RNA-recognition motifs (RRMs), RRM1 and RRM2. Understanding the structural elements by which hnRNP A1 interacts with RNA will have broad implications for studies of RNA processing. RESULTS: The crystal structure of UP1 has been determined to 1.9 A resolution. Each RRM independently adopts the characteristic RRM fold, consisting of a four-stranded antiparallel beta-pleated sheet and two alpha helices packed on one side of the beta sheet. The two RRMs are antiparallel and held in close contact, mainly by two Arg-Asp ion pairs. As a result, the two four-stranded beta sheets are brought together to form an extended RNA-binding surface. A segment of the linker connecting the two RRMs is flexible in the absence of bound RNA, but the general location of the linker suggests that it can make direct contacts with RNA. Comparison with other RRM structures indicates that a short 310 helix, found immediately N-terminal to the first beta strand in RRM1, may interact with RNA directly. CONCLUSIONS: The RRM is one of the most common and best characterized RNA-binding motifs. In certain cases, one RRM is sufficient for sequence-specific and high affinity RNA binding; but in other cases, synergy between several RRMs within a single protein is required. This study shows how two RRMs are organized in a single polypeptide. The two independently folded RRMs in UP1 are held together in a fixed geometry, enabling the two RRMs to function as a single entity in binding RNA, and so explaining the synergy between the RRMs. The UP1 structure also suggests that residues which lie outside of the RRMs can make potentially important interactions with RNA. Crystal structure of human UP1, the domain of hnRNP A1 that contains two RNA-recognition motifs.,Xu RM, Jokhan L, Cheng X, Mayeda A, Krainer AR Structure. 1997 Apr 15;5(4):559-70. PMID:9115444 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Nucleoprotein 3D structures

spinqualitylabelsall models 1up1, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image