This corresponds to a single point in the u,v domain.

Heavy-chain antibodies can bind antigens despite having only V domains.

The ability of V domain dimerization to exhibit a degree of structural fluidity has previously been noted.

The protein contains an extracellular V domain, a transmembrane domain, and a cytoplasmic tail.

Despite the absence in CD2 of the usual disulphide, the positions of all the β -strands in the V domain framework are highly conserved.

Thus the angle between the respective β- sheets in CD2 differs radically (by some 60 ) from the characteristic angle of about 50 observed for V domains.

Mutational analysis and in vitro assays have shown that preassembled V and V domains can combine to form one complex in a process called independent assembly.

V-ATPase is composed of a cytosolic V domain and a transmembrane V domain.

Vma21p coordinates assembly of the V subunits as well as escorting the V domain into vesicles for transport to the Golgi (Malkus, 2004).

The actin monomer-binding region of ActA has functional properties like the WASP-Homology-2 (WH2) or V domain, but differs in the sequence.

The V domain of a WASP protein interacts with actin monomers while the CA region associates with the Arp2/3 complex to create a nucleation core.

The usual V domain dimerization is through a specialized 'three-layer' interaction involving side chains from the CC' and FG loop regions, primarily the C' and G strands.

An evolutionary pathway for dimerization has been proposed in which the interaction of V domains (through their GFCC'C β- sheets) originated as a homophilic association having 2-fold rotational symmetry.

The mammalian V domain contains tissue-specific isoforms for subunits a and d, while yeast V-ATPase contains two organelle-specific subunit isoforms of a, Vph1p, and Stv1p.

The V domain is responsible for ATP hydrolysis, whereas the V domain is responsible for proton translocation.

In vivo regulation of V-ATPase activity is accomplished by reversible dissociation of the V domain from the V domain.

As in CD4, the C'C loop is longer than in the classic V domain, represented here by REI, but unlike CD4, the orientation maintains the flat surface of the sheet.

The V domain contains tissue-specific subunit isoforms including B, C, E, and G. Mutations to the B1 isoform result in the human disease distal renal tubular acidosis and sensorineural deafness.

After initial assembly, both the insect Manduca sexta and yeast V-ATPases can reversibly disassemble into free V and V domains after a 2- to 5-minute deprivation of glucose (Kane, 1995).

The subunits belong to either the V domain (membrane associated subunits, lowercase letters on the figure) or the V domain (peripherally associated subunits, uppercase letters on the figure).

The interaction is mediated by the domain 1 GFCC'C sheet, specifically the CC' and FG loops, and as such shows some similarity to antibody V domain and CD8 dimerization, but there are also substantial differences.

The V domain contains 6 different subunits, a, d, c, c', c", and e, with the stoichiometry of the c ring still a matter of debate with a decamer being postulated for the tobacco Hornworm M. Sexta V-ATPase.

Support for independent assembly includes the findings that the assembled V domain can be found at the vacuole in the absence of the V domain, whereas free V domains can be found in the cytoplasm and not at the vacuole (Kane, 1995; Sumner, 1995).