Protein Family Models

This family includes both TraG and TraD as well as VirD4 proteins. TraG is essential for DNA transfer in bacterial conjugation. These proteins are thought to mediate interactions between the DNA-processing (Dtr) and the mating pair formation (Mpf) systems [1]. This domain interacts with the relaxosome component TraM via the latter's tetramerisation domain. TraD is a hexameric ring ATPase that forms the cytoplasmic face of the conjugative pore [2]. [1]. 11976307. TraG-like proteins of DNA transfer systems and of the Helicobacter pylori type IV secretion system: inner membrane gate for exported substrates?. Schroder G, Krause S, Zechner EL, Traxler B, Yeo HJ, Lurz R, Waksman G, Lanka E;. J Bacteriol 2002;184:2767-2779. [2]. 18717787. Structural basis of specific TraD-TraM recognition during F plasmid-mediated bacterial conjugation. Lu J, Wong JJ, Edwards RA, Manchak J, Frost LS, Glover JN;. Mol Microbiol. 2008;70:89-99. (from Pfam)

Date:

2024-10-16

The plasmid conjugative coupling protein TrwB forms hexamers from six structurally very similar protomers [1]. This hexamer contains a central channel running from the cytosolic pole (made up by the AADs) to the membrane pole ending at the transmembrane pore shaped by 12 transmembrane helices, rendering an overall mushroom-like structure. The TrwB_AAD (all-alpha domain) domain appears to be the DNA-binding domain of the structure. TrwB, a basic integral inner-membrane nucleoside-triphosphate-binding protein, is the structural prototype for the type IV secretion system coupling proteins, a family of proteins essential for macromolecular transport between cells and export [2]. [1]. 11214325. The bacterial conjugation protein TrwB resembles ring helicases and F1-ATPase. Gomis-Ruth FX, Moncalian G, Perez-Luque R, Gonzalez A, Cabezon E, de la Cruz F, Coll M;. Nature. 2001;409:637-641. [2]. 11748238. Conjugative plasmid protein TrwB, an integral membrane type IV secretion system coupling protein. Detailed structural features and mapping of the active site cleft. Gomis-Ruth FX, Moncalian G, de la Cruz F, Coll M;. J Biol Chem. 2002;277:7556-7566. (from Pfam)

Date:

2024-10-16

This entry represents the central domain found in archaeal proteins such as DNA double-strand break repair helicase HerA (EC:3.6.4.12). HerA is a helicase which is able to utilise either 3' or 5' single-stranded DNA extensions for loading and subsequent DNA duplex unwinding [1]. It forms a complex with NurA nuclease, this complex has the 5'-3' DNA end resection activity and is essential for cell viability in the crenarchaeon Sulfolobus islandicus [2]. This domain includes the the central RecA-like catalytic core and a flanking four-helix bundle [3]. The function of this prokaryotic domain is unknown. It contains several conserved aspartates and histidines that could be metal ligands. [1]. 14990749. A bipolar DNA helicase gene, herA, clusters with rad50, mre11 and nurA genes in thermophilic archaea. Constantinesco F, Forterre P, Koonin EV, Aravind L, Elie C;. Nucleic Acids Res. 2004;32:1439-1447. [2]. 25880130. Efficient 5'-3' DNA end resection by HerA and NurA is essential for cell viability in the crenarchaeon Sulfolobus islandicus. Huang Q, Liu L, Liu J, Ni J, She Q, Shen Y;. BMC Mol Biol. 2015;16:2. [3]. 25420454. Structure of the hexameric HerA ATPase reveals a mechanism of translocation-coupled DNA-end processing in archaea. Rzechorzek NJ, Blackwood JK, Bray SM, Maman JD, Pellegrini L, Robinson NP;. Nat Commun. 2014;5:5506. (from Pfam)

Date:

2024-10-16

These TraD proteins (sometimes called TraG) generally are found in conjugative-transposon-like mobile genetic elements of the class that includes SXT, an antibiotic resistance transfer element in some Vibrio cholerae strains. This TraD subfamily is rather distantly related to the well-characterized TraD of the F plasmid.

Gene:

traD

Date:

2024-08-07