scholarly journals Escherichia coli Signal Peptidases Cleave the Signal Sequence of TK0522, a Carbohydrate Esterase from Hyperthermophilic Archaeon Thermococcus kodakarensis

2019 ◽  
Vol 52 (2) ◽  
Author(s):  
Anam Tariq ◽  
Alina Gul ◽  
Majida Atta Muhammad ◽  
Samia Falak ◽  
Naeem Rashid
Keyword(s):  
Escherichia Coli ◽  
Signal Sequence ◽  
Hyperthermophilic Archaeon ◽  
Carbohydrate Esterase ◽  
Thermococcus Kodakarensis ◽  
Signal Peptidases

Complete signal peptide of Tk1884, an α-amylase from Thermococcus kodakarensis, is not necessary for extracellular secretion of the enzyme by Escherichia coli

Amylase ◽  
2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Majida A. Muhammad ◽  
Samia Falak ◽  
Naeem Rashid ◽  
Nasir Ahmed ◽  
Qurra-Tul-Ann A. Gardner ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Recombinant Protein ◽  
Signal Peptide ◽  
Amylase Activity ◽  
Signal Sequence ◽  
Ionization Mass ◽  
Extracellular Medium ◽  
E Coli ◽  
Thermococcus Kodakarensis ◽  
Extracellular Secretion

AbstractIn order to elucidate if Escherichia coli secretion system recognizes the N-terminally truncated signal sequence of an archaeal α-amylase from Thermococcus kodakarensis (Tk1884) and secretes the recombinant protein to the extracellular medium, we have cloned Tk1884 with the deletion of the sixteen N-terminal amino acids and produced the recombinant protein Tk1884Δ16 in E. coli. Analysis of the intracellular, membranous and extracellular fractions demonstrated the presence of Tk1884Δ16 in all the three fractions. The intracellular α-amylase activity, similar to the membranous fraction, increased with the passage of time till 8 h of induction and then decreased. In contrast, the extracellular α-amylase activity slowly increased with the passage of time after induction. The extracellular amylase activity was purified and determination of the molecular mass by electrospray ionization mass spectrometry demonstrated that Tk1884Δ16 was secreted to the extracellular medium without cleavage of the signal peptide. To the best of our knowledge, this is the first report on recognition of N-terminally truncated signal peptide of archaeal origin by E. coli.

scholarly journals Characterization and in Vivo Cloning of prlC, a Suppressor of Signal Sequence Mutations in Escherichia coli K12

Genetics ◽  
1987 ◽  
Vol 116 (4) ◽  
pp. 513-521
Author(s):  
Nancy J Trun ◽  
Thomas J Silhavy
Keyword(s):  
Escherichia Coli ◽  
Genetic Mapping ◽  
Signal Sequence ◽  
Illegitimate Recombination ◽  
Mutant Phenotype ◽  
E Coli ◽  
Physical Location ◽  
Sequence Deletion ◽  
New Alleles

ABSTRACT The prlC gene of E. coli was originally identified as an allele, prlC1, which suppresses certain signal sequence mutations in the genes for several exported proteins. We have isolated six new alleles of prlC that also confer this phenotype. These mutations can be placed into three classes based on the degree to which they suppress the lamBsignal sequence deletion, lamBs78. Genetic mapping reveals that the physical location of the mutations in prlC correlates with the strength of the suppression, suggesting that different regions of the gene can be altered to yield a suppressor phenotype. We also describe an in vivo cloning procedure using λplacMu9H. The procedure relies on transposition and illegitimate recombination to generate a specialized transducing phage that carries prlC1. This method should be applicable to any gene for which there is a mutant phenotype.

scholarly journals Archaeal Binding Protein-Dependent ABC Transporter: Molecular and Biochemical Analysis of the Trehalose/Maltose Transport System of the Hyperthermophilic Archaeon Thermococcus litoralis

1998 ◽  
Vol 180 (3) ◽  
pp. 680-689 ◽  
Author(s):  
Reinhold Horlacher ◽  
Karina B. Xavier ◽  
Helena Santos ◽  
Jocelyne DiRuggiero ◽  
Marina Kossmann ◽  
...  
Keyword(s):  
Transport System ◽  
Signal Sequence ◽  
Binding Protein ◽  
Inducible Promoter ◽  
Transport Systems ◽  
Thermococcus Litoralis ◽  
Hyperthermophilic Archaeon ◽  
E Coli ◽  
Transmembrane Segments ◽  
Maltose Transport

ABSTRACT We report the cloning and sequencing of a gene cluster encoding a maltose/trehalose transport system of the hyperthermophilic archaeonThermococcus litoralis that is homologous to themalEFG cluster encoding the Escherichia colimaltose transport system. The deduced amino acid sequence of themalE product, the trehalose/maltose-binding protein (TMBP), shows at its N terminus a signal sequence typical for bacterial secreted proteins containing a glyceride lipid modification at the N-terminal cysteine. The T. litoralis malE gene was expressed in E. coli under control of an inducible promoter with and without its natural signal sequence. In addition, in one construct the endogenous signal sequence was replaced by the E. coli MalE signal sequence. The secreted, soluble recombinant protein was analyzed for its binding activity towards trehalose and maltose. The protein bound both sugars at 85°C with aKd of 0.16 μM. Antibodies raised against the recombinant soluble TMBP recognized the detergent-soluble TMBP isolated from T. litoralis membranes as well as the products from all other DNA constructs expressed in E. coli. Transmembrane segments 1 and 2 as well as the N-terminal portion of the large periplasmic loop of the E. coli MalF protein are missing in the T. litoralis MalF. MalG is homologous throughout the entire sequence, including the six transmembrane segments. The conserved EAA loop is present in both proteins. The strong homology found between the components of this archaeal transport system and the bacterial systems is evidence for the evolutionary conservation of the binding protein-dependent ABC transport systems in these two phylogenetic branches.

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