cd06193, siderophore_interacting, Siderophore interacting proteins share the domain structure of the ferredoxin reductase like family. Siderophores are produced in various bacteria (and some plants) to extract iron from hosts. Binding constants are high, so iron can be pilfered from transferrin and lactoferrin for bacterial uptake, contributing to pathogen virulence. Ferredoxin reductase (FNR), an FAD and NAD(P) binding protein, was intially identified as a chloroplast reductase activity, catalyzing the electron transfer from reduced iron-sulfur protein ferredoxin to NADP+ as the final step in the electron transport mechanism of photosystem I. FNR transfers electrons from reduced ferredoxin to FAD (forming FADH2 via a semiquinone intermediate) and then transfers a hydride ion to convert NADP+ to NADPH. FNR has since been shown to utilize a variety of electron acceptors and donors and has a variety of physiological functions including nitrogen assimilation, dinitrogen fixation, steroid hydroxylation, fatty acid metabolism, oxygenase activity, and methane assimilation in a variety of organisms. FNR has an NAD(P)-binding sub-domain of the alpha/beta class and a discrete (usually N-terminal) flavin sub-domain which vary in orientation with respect to the NAD(P) binding domain. The N-terminal moeity may contain a flavin prosthetic group (as in flavoenzymes) or use flavin as a substrate. Because flavins such as FAD can exist in oxidized, semiquinone (one-electron reduced), or fully reduced hydroquinone forms, FNR can interact with one and two electron carriers. FNR has a strong preference for NADP(H) vs NAD(H).
cd06288, PBP1_sucrose_transcription_regulator, ligand-binding domain of DNA-binding regulatory proteins specific to sucrose that are members of the LacI-GalR family of bacterial transcription repressors. This group includes the ligand-binding domain of DNA-binding regulatory proteins specific to sucrose that are members of the LacI-GalR family of bacterial transcription repressors. The LacI-GalR family repressors are composed of two functional domains: an N-terminal HTH (helix-turn-helix) domain, which is responsible for the DNA-binding specificity, and a C-terminal ligand-binding domain, which is homologous to the sugar-binding domain of ABC-type transport systems that contain the type 1 periplasmic binding protein-like fold. As also observed in the periplasmic binding proteins, the C-terminal domain of the bacterial transcription repressor undergoes a conformational change upon ligand binding which in turn changes the DNA binding affinity of the repressor.
cd05283, CAD1, Cinnamyl alcohol dehydrogenases (CAD). Cinnamyl alcohol dehydrogenases (CAD), members of the medium chain dehydrogenase/reductase family, reduce cinnamaldehydes to cinnamyl alcohols in the last step of monolignal metabolism in plant cells walls. CAD binds 2 zinc ions and is NADPH- dependent. CAD family members are also found in non-plant species, e.g. in yeast where they have an aldehyde reductase activity. The medium chain dehydrogenases/reductase (MDR)/zinc-dependent alcohol dehydrogenase-like family, which contains the zinc-dependent alcohol dehydrogenase (ADH-Zn) and related proteins, is a diverse group of proteins related to the first identified member, class I mammalian ADH. MDRs display a broad range of activities and are distinguished from the smaller short chain dehydrogenases (~ 250 amino acids vs. the ~ 350 amino acids of the MDR). The MDR proteins have 2 domains: a C-terminal NAD(P) binding-Rossmann fold domain of a beta-alpha form and an N-terminal catalytic domain with distant homology to GroES. The MDR group contains a host of activities, including the founding alcohol dehydrogenase (ADH), quinone reductase, sorbitol dehydrogenase, formaldehyde dehydrogenase, butanediol DH, ketose reductase, cinnamyl reductase, and numerous others. The zinc-dependent alcohol dehydrogenases (ADHs) catalyze the NAD(P)(H)-dependent interconversion of alcohols to aldehydes or ketones. Active site zinc has a catalytic role, while structural zinc aids in stability. ADH-like proteins typically form dimers (typically higher plants, mammals) or tetramers (yeast, bacteria), and generally have 2 tightly bound zinc atoms per subunit. The active site zinc is coordinated by a histidine, two cysteines, and a water molecule. The second zinc seems to play a structural role, affects subunit interactions, and is typically coordinated by 4 cysteines.
cd13560, PBP2_taurine, Taurine-binding periplasmic protein; the type 2 periplasmic binding protein fold. This subfamily includes the periplasmic component of putative ABC-type sulfonate transport system similar to SsuA. These domains are found in eubacterial SsuA proteins that serve as initial receptors in the ABC transport of bicarbonate, nitrate, taurine, or a wide range of aliphatic sulfonates, while other closest homologs are involved in thiamine (vitamin B1) biosynthetic pathway and desulfurization (DszB). After binding the ligand, SsuA interacts with a cognate membrane transport complex comprised of two integral membrane domains and two cytoplasmically located ATPase domains. This interaction triggers the ligand translocation across the cytoplasmic membrane energized by ATP hydrolysis. The SsuA proteins belong to the PBP2 superfamily of periplasmic binding proteins that differ in size and ligand specificity, but have similar tertiary structures consisting of two globular subdomains connected by a flexible hinge. They have been shown to bind their ligand in the cleft between these domains in a manner resembling a Venus flytrap.
pfam05110, AF-4, AF-4 proto-oncoprotein. This family consists of AF4 (Proto-oncogene AF4) and FMR2 (Fragile X E mental retardation syndrome) nuclear proteins. These proteins have been linked to human diseases such as acute lymphoblastic leukaemia and mental retardation. The family also contains a Drosophila AF4 protein homolog Lilliputian which contains an AT-hook domain. Lilliputian represents a novel pair-rule gene that acts in cytoskeleton regulation, segmentation and morphogenesis in Drosophila.
TIGR03565, alk_sulf_monoox, alkanesulfonate monooxygenase, FMNH(2)-dependent. Members of this protein family are monooxygenases that catalyze desulfonation of aliphatic sulfonates such as methane sulfonate. This enzyme uses reduced FMN, although various others members of the same luciferase-like monooxygenase family (pfam00296) are F420-dependent enzymes. [Central intermediary metabolism, Sulfur metabolism].
pfam00583, Acetyltransf_1, Acetyltransferase (GNAT) family. This family contains proteins with N-acetyltransferase functions such as Elp3-related proteins.
smart00903, Flavin_Reduct, Flavin reductase like domain. This entry represents the FMN-binding domain found in NAD(P)H-flavin oxidoreductases (flavin reductases), a class of enzymes capable of producing reduced flavin for bacterial bioluminescence and other biological processes. This domain is also found in various other oxidoreductase and monooxygenase enzymes... This domain consists of a beta-barrel with Greek key topology, and is related to the ferredoxin reductase-like FAD-binding domain. The flavin reductases have a different dimerisation mode than that found in the PNP oxidase-like family, which also carries an FMN-binding domain with a similar topology.
pfam12089, DUF3566, Transmembrane domain of unknown function (DUF3566). This family of proteins is functionally uncharacterized. This protein is found in bacteria. Proteins in this family are typically between 136 to 304 amino acids in length. This region represents a transmembrane region found at the C-terminus of the proteins.
cd03293, ABC_NrtD_SsuB_transporters, ATP-binding cassette domain of the nitrate and sulfonate transporters. NrtD and SsuB are the ATP-binding subunits of the bacterial ABC-type nitrate and sulfonate transport systems, respectively. ABC transporters are a large family of proteins involved in the transport of a wide variety of different compounds, like sugars, ions, peptides, and more complex organic molecules. The nucleotide binding domain shows the highest similarity between all members of the family. ABC transporters are a subset of nucleotide hydrolases that contain a signature motif, Q-loop, and H-loop/switch region, in addition to, the Walker A motif/P-loop and Walker B motif commonly found in a number of ATP- and GTP-binding and hydrolyzing proteins.
The bacterium proteins that are colored denote the protein is present at specific phage-related keywords (such as 'capsid', 'head', 'integrase', 'plate', 'tail', 'fiber', 'coat', 'transposase', 'portal', 'terminase', 'protease' or 'lysin' and 'tRNA')