| Primary Identifier | IPR012410 | Type | Family |
| Short Name | NDK_H5 |
| description | This family contains homologues of nucleoside diphosphate kinases (NDPKs). They are designated NDP kinase homologue 5 (NDK-H5), and differ from other NDPKs by having a C-terminal Dpy-30 motif. Despite considerable sequence similarity to other NDPKs, and conservation of seven out of nine known functionally important residues [, , ], human NDK-H5 (nm23-H5) seems to lack NDP kinase activity []. The nature of the sequence features specific to the NDK-H5 as compared to other NDPKs suggests that it may be unable to form hexamers and instead have a dimeric structure, which may affect its catalytic activity.NDK-H5 is thought to be involved in early stages of spermatogenesis []. Heterologous expression of murine NDK-H5 (nm23-M5) in yeast cells confers protection from cell death induced by Bax, which is due to the generation of reactive oxygen species, and over-expression of nm23-M5 in fibroblasts alters cellular levels of several antioxidant enzymes including Gpx5 []. Therefore, nm23-M5 may play a role in late spermatogenesis by increasing the ability of late-stage spermatids to eliminate reactive oxygen species []. |
