Common principles in the biosynthesis of diverse enzymes

A subset of bacterial periplasmic enzymes are transported from the cytoplasm by the twin-arginine transport apparatus. Such proteins contain distinctive N-terminal signal peptides containing a conserved SRRXFLK ‘twin-arginine’ amino acid motif and often bind complex cofactors before the transport event. It is important that assembly of complex cofactor-containing, and often multi-subunit, enzymes is complete before export. Studies of the unrelated [NiFe] hydrogenase, DMSO reductase and trimethylamine N-oxide reductase systems from Escherichia coli have enabled us to define a chaperone-mediated ‘proofreading’ mechanism involved in co-ordinating assembly and export of twin-arginine transport-dependent enzymes.

Download Full-text

Expression in Escherichia Coli of a Single - Chain Variable - Fragment ( scFv ) Against the Amino Acid Motif DELLA of Plant Transcription Factor Is Toxic to E. Coli

International Journal for Sciences and Technology ◽

10.12816/0010080 ◽

2013 ◽

Vol 8 (4) ◽

pp. 19-26

Author(s):

Taha Al-Samarrai

Keyword(s):

Escherichia Coli ◽

Transcription Factor ◽

Amino Acid ◽

Single Chain Variable Fragment ◽

Single Chain ◽

Amino Acid Motif ◽

E Coli ◽

Expression In Escherichia Coli

Download Full-text

ragp: Pipeline for mining of plant hydroxyproline-rich glycoproteins with implementation in R

Glycobiology ◽

10.1093/glycob/cwz072 ◽

2019 ◽

Vol 30 (1) ◽

pp. 19-35 ◽

Cited By ~ 3

Author(s):

Milan B Dragićević ◽

Danijela M Paunović ◽

Milica D Bogdanović ◽

Sladjana I .Todorović ◽

Ana D Simonović

Keyword(s):

Amino Acid ◽

Sequence Data ◽

R Package ◽

Signal Peptides ◽

Amino Acid Motif ◽

Glycosylation Sites ◽

Go Enrichment ◽

Efficient Communication ◽

Protein Backbones ◽

Proline Hydroxylation

Abstract Hydroxyproline-rich glycoproteins (HRGPs) are one of the most complex families of macromolecules found in plants, due to the diversity of glycans decorating the protein backbone, as well as the heterogeneity of the protein backbones. While this diversity is responsible for a wide array of physiological functions associated with HRGPs, it hinders attempts for homology-based identification. Current approaches, based on identifying sequences with characteristic motifs and biased amino acid composition, are limited to prototypical sequences. Ragp is an R package for mining and analysis of HRGPs, with emphasis on arabinogalactan proteins. The ragp filtering pipeline exploits one of the HRGPs key features, the presence of hydroxyprolines which represent glycosylation sites. Main package features include prediction of proline hydroxylation sites, amino acid motif and bias analyses, efficient communication with web servers for prediction of N-terminal signal peptides, glycosylphosphatidylinositol modification sites and disordered regions and the ability to annotate sequences through hmmscan and subsequent GO enrichment, based on predicted Pfam domains. As such, ragp extends R’s rich ecosystem for high-throughput sequence data analyses. The ragp R package is available under the MIT Open Source license and is freely available to download from GitHub at: https://github.com/missuse/ragp.

Download Full-text

The twin-arginine transport system: moving folded proteins across membranes

Biochemical Society Transactions ◽

10.1042/bst0350835 ◽

2007 ◽

Vol 35 (5) ◽

pp. 835-847 ◽

Cited By ~ 81

Author(s):

F. Sargent

Keyword(s):

Protein Targeting ◽

Plant Mitochondria ◽

Global Scale ◽

Signal Peptides ◽

Amino Acid Motif ◽

Transport Pathway ◽

Arginine Transport ◽

Cytoplasmic Membranes ◽

Genes Encoding ◽

Folded Proteins

The Tat (twin-arginine transport) pathway is a protein-targeting system dedicated to the transmembrane translocation of fully folded proteins. This system is highly prevalent in the cytoplasmic membranes of bacteria and archaea, and is also found in the thylakoid membranes of plant chloroplasts and possibly also in the inner membrane of plant mitochondria. Proteins are targeted to a membrane-embedded Tat translocase by specialized N-terminal twin-arginine signal peptides bearing an SRRXFLK amino acid motif. The genes encoding components of the Tat translocase were discovered approx. 10 years ago, and, since then, research in this area has expanded on a global scale. In this review, the key discoveries in this field are summarized, and recent studies of bacterial twin-arginine signal-peptide-binding proteins are discussed.

Download Full-text