RING domain

Such results were supposed to correspond to an increase in the size and/or number of the sp -carbon condensed ring domains present in the films upon increasing temperature, up to graphitization at 600 °C. After that, the expected behavior for graphitized carbon, the decrease of /d//g upon the increase of crystal size is observed. 

Fig. 4.5. Parkin and RBR proteins (A) Schematic of Parkin. (B) Alignment ofRINC-IBR-RING domains of RBR proteins.

Zheng, N., et al.. Structure of a c-Cbl-UbcH7 complex RING domain function in ubiquitin-protein ligases. Cell, 2000, 102(4), 533-9. 

Deeeenbaugh, a. E., et al.. Release of ubiquitin-charged Cdc34-S - Ub from the RING domain is essential for ubiquitination of the SCF(Cdc4)-bound substrate Sicl. Cell, 2003,... 

Hu, G. and E. R. Fearon, Siah-1 N-terminal RING domain is required for proteolysis function, and C-terminal... 

Kentsis, a., R. E. Gordon, and K. L. Borden, Self-assembly properties of a model RING domain. Proc Natl Acad Sci USA, 2002, 99(2), 667-72. 

POYUROVSKY, M. V., et ah. Nucleotide binding by the Mdm2 RING domain facilitates Arf-independent Mdm2 nucleolar localization. Mol Cell, 2003, 12(4), 875-87. 

After E2/ubiquitin thiol ester formation, the ubiquitin must be transferred to the substrate, which is sometimes another ubiquitin. An E3 is usually required for this reaction in vitro, and is always required in vivo. There are three known types of E3s the RING domain, HECT domain, and U-box (UED2 homology) families. RING and U-box E3s act as bridging factors for E2s and substrates, but HEGT E3s use a different mechanism, adding an extra step to the pathway (Section 5.6.3.3). 

The small RING domain coordinates two zinc ions in a cross-brace arrangement [104]. The domain is defined by the presence of eight zinc-binding groups (cysteines and histidines) with a conserved spacing, such that the distance between... 

Fig. S.S. UbcH7/c-Cbl complex (IFBV).The surface of UbcH7 is shown with residues interacting with the c-Cbl RING domain shown in red and the active-site cysteine shown in yellow. c-Cbl is colored green.

The closest approach of a RING-domain residue to the active-site cysteine of UbcH7 is about 15 A, arguing against a role for RING E3s in chemical catalysis [106]. Instead, RING E3s have been proposed to facilitate ubiquitination by inducing physical proximity of the E2/ubiquitin thiol ester and the substrate [23, 30, 106, 109]. Catalysis would result from the increased local concentrations of the two reactants (discussed further below). 

RING/E2 interactions have also been studied with BRCAl. This E3 is unique in that it must heterodimerize with a second RING-domain protein, BARDl, in order to display maximal E3 activity [110]. Even though the heterodimer interface leaves... 

Borden, K L. RING domains master builders of molecular scaffolds /. Mol. Biol. 2000, 295, 1103-12. 

Fig. 7.2. Ciystal structures of ubiquitin ligases discussed in this chapter. The structures are colored as following The HECT N lobe is purple, C lobe green, and the E2 blue, the c-Cbl TKB domain is green, the linker yellow, RING domain purple, the phosphopeptide orange.

The c-Cbl-E2-ZAP70 peptide complex adapts a compact structure with multiple inter- and intra-molecular interfaces (Figure 7.2) [49]. The RING domain is anchored on the TKB domain through extensive interactions with the 4H bundle, whde the linker forms an ordered loop and an a-helix, which packs closely with... 

The SCF and SCF-like complexes are multi-subunit RING-type E3s that represent the largest E3 family knotvn to date. This superfamily of E3s are involved in regulating cell-cycle progression, signal transduction pathways, transcriptional control, and multiple aspects of cell growth and development (reviewed in Ref. [50]). All members of this E3 superfamily contain two basic components, a member of the cullin protein family and a RING-domain protein. The cullin subumt serves as the... 

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