2kox
From Proteopedia
NMR residual dipolar couplings identify long range correlated motions in the backbone of the protein ubiquitin
Structural highlights
FunctionRL40_HUMAN Ubiquitin exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, DNA-damage responses as well as in signaling processes leading to activation of the transcription factor NF-kappa-B. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling.[1] [2] Ribosomal protein L40 is a component of the 60S subunit of the ribosome.[3] [4] Publication Abstract from PubMedLong-range correlated motions in proteins are candidate mechanisms for processes that require information transfer across protein structures, such as allostery and signal transduction. However, the observation of backbone correlations between distant residues has remained elusive, and only local correlations have been revealed using residual dipolar couplings measured by NMR spectroscopy. In this work, we experimentally identified and characterized collective motions spanning four beta-strands separated by up to 15 A in ubiquitin. The observed correlations link molecular recognition sites and result from concerted conformational changes that are in part mediated by the hydrogen-bonding network. Weak Long-Range Correlated Motions in a Surface Patch of Ubiquitin Involved in Molecular Recognition.,Fenwick RB, Esteban-Martin S, Richter B, Lee D, Walter KF, Milovanovic D, Becker S, Lakomek NA, Griesinger C, Salvatella X J Am Chem Soc. 2011 Jul 13;133(27):10336-10339. Epub 2011 Jun 20. PMID:21634390[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Homo sapiens | Large Structures | Becker S | Fenwick RB | Griesinger C | Lakomek NA | Lee D | Milovanovic D | Richter B | Salvatella X | Walter KFA
