Primary Citation of Related Structures: 1PJM, 1PJN
PubMed Abstract:
Importin-alpha is the nuclear import receptor that recognizes cargo proteins carrying conventional basic monopartite and bipartite nuclear localization sequences (NLSs) and facilitates their transport into the nucleus. Bipartite NLSs contain two clusters of basic residues, connected by linkers of variable lengths ...
Importin-alpha is the nuclear import receptor that recognizes cargo proteins carrying conventional basic monopartite and bipartite nuclear localization sequences (NLSs) and facilitates their transport into the nucleus. Bipartite NLSs contain two clusters of basic residues, connected by linkers of variable lengths. To determine the structural basis of the recognition of diverse bipartite NLSs by mammalian importin-alpha, we co-crystallized a non-autoinhibited mouse receptor protein with peptides corresponding to the NLSs from human retinoblastoma protein and Xenopus laevis phosphoprotein N1N2, containing diverse sequences and lengths of the linker. We show that the basic clusters interact analogously in both NLSs, but the linker sequences adopt different conformations, whereas both make specific contacts with the receptor. The available data allow us to draw general conclusions about the specificity of NLS binding by importin-alpha and facilitate an improved definition of the consensus sequence of a conventional basic/bipartite NLS (KRX10-12KRRK) that can be used to identify novel nuclear proteins.
Related Citations:
Structural basis of recognition of monopartite and bipartite nuclear localization sequences by mammalian importin-alpha Fontes, M.R.M., Teh, T., Kobe, B. (2000) J Mol Biol 297: 1183
Biophysical Characterization of Interactions Involving Impostin-alpha during Nuclear Import Catimel, B., Teh, T., Fontes, M.R.M., Jennings, I.G., Jans, D., Howlett, G.J., Nice, E.C., Kobe, B. (2001) J Biol Chem 276: 34189
Autoinhibition by an internal nuclear localization signal reveled by the crystal structure of mammalian importin alpha Kobe, B. (1999) Nat Struct Biol 6: 388
Organizational Affiliation:
Structural Biology Laboratory, St. Vincent's Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065, Australia.
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