<p>6-phosphogluconate dehydrogenase (<db_xref db="EC" dbkey="1.1.1.44"/>) catalyses the oxidative decarboxylation of 6-phosphogluconate to ribulose 5-phosphate with the concomitant reduction of NADP to NADPH. This reaction is a component of the hexose mono-phosphate shunt and pentose phosphate pathways (PPP), which functions to generate ribose 5-phosphate for nucleotide and nucleic acid synthesis [<cite idref="PUB00002112"/>, <cite idref="PUB00001132"/>]. Prokaryotic and eukaryotic 6PGD are proteins of about 470 amino acids whose sequences are highly conserved [<cite idref="PUB00003806"/>]. The protein is a homodimer in which the monomers act independently: each contains a large, mainly alpha-helical domain and a smaller beta-alpha-beta domain, containing a mixed parallel and anti-parallel 6-stranded beta sheet [<cite idref="PUB00001132"/>]. NADP is bound in a cleft in the small domain, and the substrate binds in an adjacent pocket [<cite idref="PUB00001132"/>]. </p><p>This entry represents the terminal 30-40 residues of 6-phosphogluconate dehydrogenase C-terminal domain, which is lacking in certain 6PGD enzymes. The core of the C-terminal domain is represented by <db_xref db="INTERPRO" dbkey="IPR012283"/>. This region bears structural resemblance to the C-terminal portion of the <taxon tax_id="10665">Bacteriophage T4</taxon> fibritin protein, which is responsible for the attachment of long tail fibres to virus particles, and forms the, "whiskers", or fibres on the neck of the virion [<cite idref="PUB00016564"/>].</p> Fibritin/6-phosphogluconate dehydrogenase, C-terminal extension