1mfs
From Proteopedia
DYNAMICAL BEHAVIOR OF THE HIV-1 NUCLEOCAPSID PROTEIN; NMR, 30 STRUCTURES
Overview
The HIV-1 nucleocapsid protein (NC) contains two CCHC-type zinc knuckle domains that are essential for genome recognition, packaging and infectivity. The solution structure of the protein has been determined independently by three groups. Although the structures of the individual zinc knuckle domains are similar, two of the studies indicated that the knuckles behave as independently folded, non-interacting domains connected by a flexible tether, whereas one study revealed the presence of interknuckle NOE cross-peaks, which were interpreted in terms of a more compact structure in which the knuckles are in close proximity. We have collected multidimensional NMR data for the recombinant, isotopically labeled HIV-1 NC protein, and confirmed the presence of weak interknuckle NOEs. However, the NOE data are not consistent with a single protein conformation. 15N NMR relaxation studies reveal that the two zinc knuckle domains possess different effective rotational correlation times, indicating that the knuckles are not tumbling as a single globular domain. In addition, the 1H NMR chemical shifts of isolated zinc knuckle peptides are very similar to those of the intact protein. The combined results indicate that the interknuckle interactions, which involve the close approach of the side-chains of Phe16 and Trp37, are transitory. The solution behavior of NC may be best considered as a rapid equilibrium between conformations with weakly interacting and non-interacting knuckle domains. This inherent conformational flexibility may be functionally important, enabling adaptive binding of NC to different recognition elements within the HIV-1 psi-RNA packaging signal.
About this Structure
1MFS is a Single protein structure of sequence from Human immunodeficiency virus. Full crystallographic information is available from OCA.
Reference
Dynamical behavior of the HIV-1 nucleocapsid protein., Lee BM, De Guzman RN, Turner BG, Tjandra N, Summers MF, J Mol Biol. 1998 Jun 12;279(3):633-49. PMID:9641983 Page seeded by OCA on Sat May 3 00:58:46 2008
