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Holin Superfamily III
The Holin Superfamily III is a superfamily of integral membrane transport proteins. It is one of the seven different holin superfamilies in total. In general, these proteins are thought to play a role in regulated cell death, although functionality varies between families and individual members. Members of the holin superfamily III are derived from Pseudomonadota, Synergistota, Actinomycetota, Deinococcota, and Archaea Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac .... This superfamily includes seven TC families: 1.E.2- The λ Holin S (λ Holin) Family 1.E.3- The P2 Holin (P2 Holin) Family 1.E.4- The LydA Holin (LydA Holin) Family 1.E.5- The PRD1 Phage P35 Holin (P35 Holin) Family 1.E.20- The ''Pseudomonas aeruginosa'' Hol Holin (Hol Holin) Family 1.E.34- The Putative Actin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Superfamily
A protein superfamily is the largest grouping (clade) of proteins for which common ancestry can be inferred (see homology (biology), homology). Usually this common ancestry is inferred from structural alignment and mechanistic similarity, even if no sequence similarity is evident. Sequence homology can then be deduced even if not apparent (due to low sequence similarity). Superfamilies typically contain several protein families which show sequence similarity within each family. The term ''protein clan'' is commonly used for protease and glycosyl hydrolases superfamilies based on the MEROPS and CAZy classification systems. Identification Superfamilies of proteins are identified using a number of methods. Closely related members can be identified by different methods to those needed to group the most evolutionarily divergent members. Sequence similarity Historically, the similarity of different amino acid sequences has been the most common method of inferring Sequence homology, h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LydA Holin Family
The LydA Holin (LydA Holin) FamilyTC# 1.E.4, named after the ''lydA'' gene which codes for its prototype member (LydA of ''E. coli''TC# 1.E.4.1.1, belongs to the Holin Superfamily III. Members of this family have 3 transmembrane segments (TMSs) and appear to possess between 90 and 120 amino acyl residues (aas). A representative list of proteins belonging to this family can be found in thTransporter Classification Database See also * Holin * Lysin Lysins, also known as endolysins or murein hydrolases, are hydrolytic enzymes produced by bacteriophages in order to cleave the host's cell wall during the final stage of the lytic cycle. Lysins are highly evolved enzymes that are able to target ... * Transporter Classification Database References Holins Protein families {{membrane-protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysin
Lysins, also known as endolysins or murein hydrolases, are hydrolytic enzymes produced by bacteriophages in order to cleave the host's cell wall during the final stage of the lytic cycle. Lysins are highly evolved enzymes that are able to target one of the five bonds in peptidoglycan (murein), the main component of bacterial cell walls, which allows the release of progeny virions from the lysed cell. Cell-wall-containing Archaea are also lysed by specialized pseudomurein-cleaving lysins, while most archaeal viruses employ alternative mechanisms. Similarly, not all bacteriophages synthesize lysins: some small single-stranded DNA and RNA phages produce membrane proteins that activate the host's autolytic mechanisms such as autolysins. Lysins are being used as antibacterial agents due to their high effectiveness and specificity in comparison with antibiotics, which are susceptible to bacterial resistance. Structure Double-stranded DNA phage lysins tend to lie within the 25 to 40 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinococcus/Thermus Holin Family
The Deinococcus/Thermus Holin (D/T-Hol) FamilyTC# 1.E.41 consists of a single protein with no close homologues (Putative holin of ''Meiothermus silvanus'TC# 1.E.41.1.1; however, its distant homology to members of the Holin superfamily III suggest an evolutionary relationship. The putative holin of ''Meiothermus silvanus'' is 108 amino acyl residues in length and possesses 3 transmembrane segments. See also * Holins * Lysins * Holin superfamily III * Transporter Classification Database References Protein families Membrane proteins Transmembrane proteins Transmembrane transporters Transport proteins Integral membrane proteins {{membrane-protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Putative Actinobacterial Holin-X Family
The putative actinobacterial holin-X (Hol-X) family (TC# 1.E.34) was retrieved as a distant member of TC family 1.E.20, suggesting membership of the holin superfamily III. Most Hol-X proteins are less than 200 amino acyl residues (aas) in length and possess two transmembrane segments (TMSs). A representative list of proteins belonging to this family can be found in the Transporter Classification Database. See also * Holins * Lysins * Holin superfamily III * Transporter Classification Database References Protein families Holins {{membrane-protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonas Aeruginosa Hol Holin Family
The ''Pseudomonas aeruginosa'' Hol Holin (Hol Holin) FamilyTC# 1.E.20 is a group of transporters belonging to the Holin Superfamily III. The ''hol'' gene (PRF9) product (117 aas) of '' Pseudomonas aeruginosa'' PAO1 exhibits a hydrophobicity profile similar to holins of P2 and φCTX phages with two peaks of hydrophobicity that might correspond to either one or two transmembrane segments (TMSs). Hol functions in conjunction with the lytic enzyme, Lys (PRF24; 209 amino acyl residues (aas)). Hol by itself, when expressed in a broad host-range expression vector under IPTG control exhibited strong lytic activity in both ''P. aeruginosa'' and ''E. coli.'' Expression of the ''lys'' gene plus chloroform (but not minus chloramphenicol Chloramphenicol is an antibiotic useful for the treatment of a number of bacterial infections. This includes use as an eye ointment to treat conjunctivitis. By mouth or by injection into a vein, it is used to treat meningitis, plague, cholera, a ...) yi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P35 Holin Family
The PRD1 Phage P35 Holin (P35 Holin) FamilyTC# 1.E.5 is a member of Holin Superfamily III. The prototype for this family is the lipid-containing PRD1 enterobacterial phage holin protein P35 (12.8 kDaTC# 1.E.5.1.1 encoded by gene ''XXXV'' (''orfT''). It is a component of a typical holin-endolysin system which functions to lyse the host bacterial cell. Structure P35 holinTC# 1.E.5.1.1 has 3 transmembrane segments (TMSs) with 5 positively charged residues between TMSs 1 and 2. It has 4 positively charged residues at the C-terminus. It is therefore thought that the N-terminus is in the periplasm and the C-terminus is in the cytoplasm. Homologues of 109 amino acyl residues (aas), which also have 3 putative TMSs, are encoded in the genomes of '' Xylella fastidiosa'' strains. Function The reaction catalyzed by P35 holin is: : autolysin (in) → autolysin (out) See also * Bacteriophage * Phage typing Phage typing is a Phenotype, phenotypic method that uses Bacteriophage, bacterio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambda Holin Family
The Lambda Holin S (λ Holin) FamilyTC# 1.E.2 is a group of integral membrane transporter proteins belonging to the Holin Superfamily III. Members of this family generally consist of the characteristic three transmembrane segments (TMSs) and are of 110 amino acyl residues (aas) in length, on average. A representative list of members belonging to this family can be found in the Transporter Classification Database. Lambda Holin S Lambda holin S (Lysis protein S of phage lambda, holin S105TC# 1.E.2.1.1 is the prototype for class I holins. It has 3 TMSs with the N-terminus in the periplasm and the C-terminus in the cytoplasm. Its 107 codon sequence encodes two proteins with opposing functions, the holin, S105, and the holin inhibitor, S107. The latter protein, S107, is a 2-amino acid extension of the former protein, S105, due to a different translational initiation start site (M1-K2-M3 vs. M3). A cationic amino acid at position 2 is largely responsible for the inhibiting effect of S1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Transport Protein
A membrane transport protein (or simply transporter) is a membrane protein involved in the movement of ions, small molecules, and macromolecules, such as another protein, across a biological membrane. Transport proteins are integral transmembrane proteins; that is they exist permanently within and span the membrane across which they transport substances. The proteins may assist in the movement of substances by facilitated diffusion or active transport. The two main types of proteins involved in such transport are broadly categorized as either ''channels'' or ''carriers''. The solute carriers and atypical SLCs are secondary active or facilitative transporters in humans. Collectively membrane transporters and channels are known as the transportome. Transportomes govern cellular influx and efflux of not only ions and nutrients but drugs as well. Difference between channels and carriers A carrier is not open simultaneously to both the extracellular and intracellular environments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this term has fallen out of use. Archaeal cells have unique properties separating them from the other two domains, Bacteria and Eukaryota. Archaea are further divided into multiple recognized phyla. Classification is difficult because most have not been isolated in a laboratory and have been detected only by their gene sequences in environmental samples. Archaea and bacteria are generally similar in size and shape, although a few archaea have very different shapes, such as the flat, square cells of ''Haloquadratum walsbyi''. Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably for the enzymes involved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinococcota
''Deinococcota'' (synonym, ''Deinococcus-Thermus'') is a phylum of bacteria with a single class, ''Deinococci'', that are highly resistant to environmental hazards, also known as extremophiles. These bacteria have thick cell walls that give them gram-positive stains, but they include a second membrane and so are closer in structure to those of gram-negative bacteria. Taxonomy The phylum ''Deinococcota'' consists of a single class (''Deinococci'') and two orders: * The ''Deinococcales'' include two families (''Deinococcaceae'' and'' Trueperaceae''), with three genera, ''Deinococcus'', ''Deinobacterium'' and ''Truepera''.Garrity GM, Holt JG. (2001) Phylum BIV. "Deinococcus–Thermus". In: Bergey’s manual of systematic bacteriology, pp. 395-420. Eds D. R. Boone, R. W. Castenholz. Springer-: New York.Garrity GM, Bell JA, Lilburn TG. (2005) Phylum BIV. The revised road map to the Manual. In: Bergey’s manual of systematic bacteriology, pp. 159-220. Eds Brenner DJ, Krieg NR, Staley ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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