PMC:2728203 / 17568-19003 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/2728203","sourcedb":"PMC","sourceid":"2728203","source_url":"https://www.ncbi.nlm.nih.gov/pmc/2728203","text":"Similarity to the PWI fold\nA search for structural homologues of the Nab2 N-terminal domain using the DALI web site† indicated that it had distant similarity to the PWI domain fold (Fig. 4) that is found in a number of nucleic acid binding proteins such as the splicing factor and exon junction component SRm160.30,34 The Pro-Trp-Ile sequence for which the PWI domain is named is found in helix H1 of this fold and is important in generating the hydrophobic core of the PWI fold in which the Trp and Ile side chains pack against Phe101 in helix H4 of SRm160. The PWI fold is thought to bind both single- and double-stranded DNA and RNA through a characteristic basic patch on its surface.34 However, there is little conservation at the sequence level, and the characteristic Pro-Trp-Ile (PWI) sequence motif is not present in the Nab2 N-terminal domain where the corresponding residues are Val12, Ile13, and Val14. Similarly, Nab2 lacks the characteristic positively charged surface patch that has been associated with nucleic acid binding.34 Moreover, the nucleic acid binding function of SRm160 also requires residues upstream of the PWI domain34 that are lacking in the Nab2 N-terminal domain, and, consistent with this observation, we were unable to detect any interaction between the Nab2 N-terminal domain and poly(N) RNA in band-shift assays under conditions where the PWI domain from SRm160 showed a clear interaction (Fig. 5).","divisions":[{"label":"title","span":{"begin":0,"end":26}}],"tracks":[{"project":"2_test","denotations":[{"id":"18190927-10322432-62517991","span":{"begin":315,"end":317},"obj":"10322432"}],"attributes":[{"subj":"18190927-10322432-62517991","pred":"source","obj":"2_test"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"2_test","color":"#93c1ec","default":true}]}]}}