P-loop containing Nucleoside Triphosphate Hydrolases; Members of the P-loop NTPase domain superfamily are characterized by a conserved nucleotide phosphate-binding motif, also referred to as the Walker A motif (GxxxxGK[S/T], where x is any residue), and the Walker B motif (hhhh[D/E], where h is a hydrophobic residue). The Walker A and B motifs bind the beta-gamma phosphate moiety of the bound nucleotide (typically ATP or GTP) and the Mg2+ cation, respectively. The P-loop NTPases are involved in diverse cellular functions, and they can be divided into two major structural classes: the KG (kinase-GTPase) class which includes Ras-like GTPases and its circularly permutated YlqF-like; and the ASCE (additional strand catalytic E) class which includes ATPase Binding Cassette (ABC), DExD/H-like helicases, 4Fe-4S iron sulfur cluster binding proteins of NifH family, RecA-like F1-ATPases, and ATPases Associated with a wide variety of Activities (AAA). Also included are a diverse set of nucleotide/nucleoside kinase families.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148223816   35 ECGFTVDLDALDCDLARNVFGQHLARELLFKSVKEFIENDNPSKPLVLSLHGWSGTGKTFVSSLLVKHLFKEGSQSRFVH 114
Cdd:pfam06309   2 DCRISFNYTGLERDLARRLFGQHLVKQLVVRSVKGHWENPKPRKPLVLSFHGWTGTGKNFVAEIIADNLYRDGLRSDYVH 81

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 148223816  115 FFSPVLHFPRVQNLEQYKVDLKGWIQGNLTTCSRSLFVF 153
Cdd:pfam06309  82 HFVATFHFPHPKYVELYKVELKNQIRGTLRACHRSIFIF 120

Torsin; This family consists of several eukaryotic torsin proteins. Torsion dystonia is an autosomal dominant movement disorder characterized by involuntary, repetitive muscle contractions and twisted postures. The most severe early-onset form of dystonia has been linked to mutations in the human DYT1 (TOR1A) gene encoding a protein termed torsinA. While causative genetic alterations have been identified, the function of torsin proteins and the molecular mechanism underlying dystonia remain unknown. Phylogenetic analysis of the torsin protein family indicates these proteins share distant sequence similarity with the large and diverse family of (pfam00004) proteins. It has been suggested that torsins play a role in effectively managing protein folding and that possible breakdown in a neuroprotective mechanism that is, in part, mediated by torsins may be responsible for the neuronal dysfunction associated with dystonia.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148223816   35 ECGFTVDLDALDCDLARNVFGQHLARELLFKSVKEFIENDNPSKPLVLSLHGWSGTGKTFVSSLLVKHLFKEGSQSRFVH 114
Cdd:pfam06309   2 DCRISFNYTGLERDLARRLFGQHLVKQLVVRSVKGHWENPKPRKPLVLSFHGWTGTGKNFVAEIIADNLYRDGLRSDYVH 81

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 148223816  115 FFSPVLHFPRVQNLEQYKVDLKGWIQGNLTTCSRSLFVF 153
Cdd:pfam06309  82 HFVATFHFPHPKYVELYKVELKNQIRGTLRACHRSIFIF 120

Torsin; This family consists of several eukaryotic torsin proteins. Torsion dystonia is an autosomal dominant movement disorder characterized by involuntary, repetitive muscle contractions and twisted postures. The most severe early-onset form of dystonia has been linked to mutations in the human DYT1 (TOR1A) gene encoding a protein termed torsinA. While causative genetic alterations have been identified, the function of torsin proteins and the molecular mechanism underlying dystonia remain unknown. Phylogenetic analysis of the torsin protein family indicates these proteins share distant sequence similarity with the large and diverse family of (pfam00004) proteins. It has been suggested that torsins play a role in effectively managing protein folding and that possible breakdown in a neuroprotective mechanism that is, in part, mediated by torsins may be responsible for the neuronal dysfunction associated with dystonia.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148223816   35 ECGFTVDLDALDCDLARNVFGQHLARELLFKSVKEFIENDNPSKPLVLSLHGWSGTGKTFVSSLLVKHLFKEGSQSRFVH 114
Cdd:pfam06309   2 DCRISFNYTGLERDLARRLFGQHLVKQLVVRSVKGHWENPKPRKPLVLSFHGWTGTGKNFVAEIIADNLYRDGLRSDYVH 81

                          90       100       110
                  ....*....|....*....|....*....|....*....
gi 148223816  115 FFSPVLHFPRVQNLEQYKVDLKGWIQGNLTTCSRSLFVF 153
Cdd:pfam06309  82 HFVATFHFPHPKYVELYKVELKNQIRGTLRACHRSIFIF 120