Highly homologous proteins

Heterogeneous nuclear ribonucleoprotein (HNRNP) A1 and A2 are the most abundant HNRNPs with nearly identical functions, and play important roles in regulating gene expression at multiple levels (i.e. transcription, posttranscription, and translation). However, the expression and regulation mechanism of HNRNPA1 and A2 themselves remain unclear. In this study, the amino acid sequences of HNRNPA1 and HNRNPA2 were compared and found to have 78% and 86% homology in key functional domains.

10p thiencuuchu 27-11-2021 10 1   Download

The plastid transcription kinase (PTK), a component of the major RNA polymerase complex from mustard chloroplasts, has been implicated in redox-mediated regulation of plastid gene expression. A cloning strategy to define the PTK gene(s) resulted in the isolation of a full-length cDNA for a protein with overall high homology with the a subunit of cytosolic casein kinase (CK2) that contained an N-terminal extension for a putative plastid transit peptide.

9p system191 01-06-2013 45 4   Download

The high-pressure stopped-flow technique is applied to study the CO binding in cytochrome P450cam (P450cam) bound with homologous substrates (1R-camphor, camphane, norcamphor and norbornane) and in the substrate-free protein. The activation volume DV # of the CO on-rate is positive for P450cam bound with substrates that do not contain methyl groups. The kon rate constant for these substrate complexes is in the order of 3 · 106 M)1Æs)1. In contrast, P450cam complexed with substrates carrying methyl groups show a negative activation volume and a low kon rate constant of % 3 · 104 M)1Æs)1. ...

8p system191 01-06-2013 38 4   Download

The present work reports isolation and characterization of a highly glycosylated protein from bovine milk fat globule membranes, known as PAS III. Partial amino-acid sequencing of the purified protein allowed construction of degenerate oligonucleotide primers, enabling isolation of a full-length cDNA encoding a protein of 330 amino-acid residues. N-terminal amino-acid sequencing of derived peptides and the purified protein confirmed 76% of the sequence and demonstrated presence of a cleavable signal peptide of 23 residues, leaving a mature protein of 307 amino acids.

9p system191 01-06-2013 49 4   Download

Two genes (CM-AAT1 and CM-AAT2) with strong sequence homology (87% identity at the protein level) putatively involved in the formation of aroma volatile esters have been isolated from Charentais melon fruit. They belong to a large and highly divergent family of multifunctional plant acyl-transferases and show at most 21% identity to the only other fruit acyl-transferase characterized so far in strawberry. RT-PCR studies indicated that both genes were specifically expressed in fruit at increasing rates in the early and mid phases of ripening.

8p research12 01-06-2013 49 4   Download

Murine pregnancy-associated plasma protein-A (PAPP-A) cDNA encoding a 1545 amino-acid protein has been cloned. We have also identified and cloned cDNA that encodes a novel variant of PAPP-A, PAPP-Ai, carrying a 29-residue highly basic insert. The point of insertion corresponds to a junction between two exons in the human PAPP-A gene. The human intron flanked by these exons does not encode a homologous corresponding insert, which is unique to the mouse.

10p research12 01-06-2013 42 6   Download

We have identified and characterized a thermostable thio-redoxin system in the aerobic hyperthermophilic archaeon AeropyrumpernixK1. Thegene (Accessionno.APE0641) of A. pernixencoding a 37 kDaprotein contains a redox active site motif (CPHC) but its N-terminal extension region (about 200 residues) shows no homologywithin the genome database. A second gene (Accession no. APE1061) has high homology to thioredoxin reductase and encodes a 37 kDa protein with the active site motif (CSVC), and binding sites forFADandNADPH....

8p tumor12 22-04-2013 33 2   Download

The analysis of the structure and function of long chain-producing polyprenyl diphosphate synthase, which syn-thesizes the side chain of ubiquinone, has largely focused on the prokaryotic enzymes, and little is known about the eukaryotic counterparts. Here we show that decaprenyl diphosphate synthase fromSchizosaccharomyces pombeis comprised of a novel protein named Dlp1 acting in part-nership with Dps1. Dps1 is highly homologous to other prenyl diphosphate synthases but Dlp1 shares only weak homologywithDps1....

9p tumor12 20-04-2013 33 2   Download

Cdc37 is a molecular chaperone that interacts with a range of clients and co-chaperones, forming various high molecular mass complexes. Cdc37 sequence homology among species is low. High homology between yeast and metazoan proteins is restricted to the extreme N-terminal region, which is known to bind clients that are predominantly protein kinases.

12p fptmusic 11-04-2013 18 1   Download

Fructose 2,6-bisphosphate is a potent allosteric activator of trypanosomatid pyruvate kinase and thus represents an important regulator of energy meta-bolism in these protozoan parasites. A 6-phosphofructo-2-kinase, respon-sible for the synthesis of this regulator, was highly purified from the bloodstream form ofTrypanosoma bruceiand kinetically characterized. By searching trypanosomatid genome databases, four genes encoding proteins homologous to the mammalian bifunctional enzyme 6-phosphofructo-2-kinase⁄fructose-2,6-bisphosphatase (PFK-2⁄FBPase-2) were found for both T. ...

19p fptmusic 11-04-2013 32 3   Download

The high water permeability of certain biological membranes is due to the presence of aquaporin water channel proteins. AQP1 was discovered in human red cells. AQP1 has been thoroughly characterized biophysically, and the atomic structure of AQP1 has been elucidated. Ten homologs have been identified in humans. These are selectively permeated by water (aquaporins) or water plus glycerol (aquaglyceroporins). The sites of expres-sion predict the clinical phenotypes in humans. Individuals lack-ing Colton blood group antigens have mutations in the AQP1 gene. ...

81p fptmusic 11-04-2013 35 4   Download

The structure of cytochromec-550 from the nonphotosynthetic bacteria Paraccocus versutushas been solved by X-ray crystallography to 1.90 A˚ resolution, and reveals a high structural homology to other bacterial cyto-chromesc2. The effect of replacing the axial heme-iron methionine ligand with a lysine residue on protein structure and unfolding has been assessed using the M100K variant.

15p awards 06-04-2013 39 3   Download

In several organisms d-cysteine desulfhydrase (d-CDes) activity (EC 4.1.99.4) was measured; this enzyme decomposes d-cysteine into pyruvate, H2S, and NH3. A gene encoding a putative d-CDes protein was identified in Arabidopsis thaliana(L) Heynh. based on high homology to an Escherichia coliprotein called YedO that hasd-CDes activity. The deduced Arabidopsisprotein consists of 401 amino acids and has a molecular mass of 43.9 kDa.

14p awards 06-04-2013 36 3   Download

Despite their high sequence homology, rubredoxins fromDesulfovibrio gigasandD. desulfuricansare stabilized to very different extents by com-patible solutes such as diglycerol phosphate, the major osmolyte in the hyperthermophilic archaeonArchaeoglobus fulgidus[Lamosa P, Burke A, Peist R, Huber R, Liu M Y, Silva G, Rodrigues-Pousada C, LeGall J, Maycock C and Santos H (2000)Appl Environ Microbiol66, 1974–1979]. The principal structural difference between these two proteins is the absence of the hairpin loop in the rubredoxin fromD. desulfuricans....

13p awards 05-04-2013 47 3   Download

The role of vertebrate histone proteins or histone derived peptides as innate immune effectors has only recently been appreciated. In this study, high levelsof corehistoneproteins H2A, H2B, H3 and H4 were found in hemocytes from the Pacific white shrimp,Litopenaeus vannamei. The proteins were identified by in-gel digestion, mass spectrometry ana-lysis, and homology searching. The L. vannameihistone proteins were found to be highly homologous to histones of other species.

0p awards 05-04-2013 28 1   Download

We reported previously that the major cysteine protease in embryos and larvaeof thebrine shrimp,Artemia franciscana, is a heterodimeric protein consisting of a catalytic subunit (28.5 kDa) with a high degree of homology with cathep-sin L, and a noncatalytic subunit (31.5 kDa) of unknown function. In the study reportedhere thenoncatalytic subunit, or cathepsin L-associated protein (CLAP), was separated from cathepsin L by chromatography on Mono S and found tocontainmultiple isoformswithpIs ranging from5.9 to 6.1.

12p awards 05-04-2013 54 4   Download

A putative phosphoglycerate dehydrogenase (PGDH), which catalyzes the oxidation ofD-phosphoglycerate to 3-phosphohydroxypyruvate in the so-called phosphorylated serine metabolic pathway, from the enteric protozoan parasite Entamoeba histolytica was characterized. The E. histolyticaPGDH gene (EhPGDH) encodes a protein of 299 amino acids with a calculated molecular mass of 33.5 kDa and an isoelectric point of8.11. EhPGDHshowed high homology to PGDH from bacteroides and another enteric protozoan ciliate,Entodinium caudatum. ...

12p dell39 03-04-2013 43 4   Download

TheB class cell-attachedephrinsmediate contact-dependent cell–cell communications and transduce the contact signals to the host cells through the binding interactions of their cytoplasmic domains. Two classes of intracellular effectors of B ephrins have been identified: one contains the PSD-95/ Dlg/ZO-1 (PDZ)domain(for examplePDZ-RGS3), and the second the Src homology 2 (SH2) domain (e.g. the Grb4 adaptor protein).

12p dell39 03-04-2013 44 5   Download

The catalytic module ofHypocrea jecorina(previously Trichoderma reesei) Cel7B was homologously expressed by transformation of strain QM9414. Post-translational modi-fications in purified Cel7B preparations were analysed by enzymatic digestions, high performance chromatography, mass spectrometry and site-directed mutagenesis. Of the five potential sites found in the wild-type enzyme, only Asn56 and Asn182 were found to be N-glycosylated.

11p dell39 03-04-2013 44 5   Download

Pigments homologous to the green fluorescent protein (GFP) contribute up to 14% of the soluble protein content of many anthozoans. Maintenance of such high tissue levels poses a severe energetic penalty to the animals if protein turnover is fast. To address this as yet unexplored issue, we estab-lished that the irreversible green-to-red conversion of the GFP-like pig-

10p galaxyss3 21-03-2013 42 3   Download