Molecular cloning and sequencing of the gene for a halophilic alkaline serine protease (halolysin) from an unidentified halophilic archaea strain (172P1) and expression of the gene in Haloferax volcanii

Abstract

The gene of a halophilic alkaline serine protease, halolysin, from an unidentified halophilic archaea (archaebacterium) was cloned and its nucleotide sequence was determined. The deduced amino acid sequence showed that halolysin consists of 411 amino acids, with a molecular weight of 41,963. The highest homology was found with thermitase from Thermoactinomyces vulgaris. Halolysin has a long C-terminal extension of approximately 120 amino acids which has not been found in other extracellular subtilisin type serine proteases. The gene, hly, was expressed in another halophilic archaea, Haloferax volcanii, in a medium containing 18% salts by using a plasmid shuttle vector which has a novobiocin resistance determinant as a selectable marker.

Isolation, sequence, and expression of the gene encoding halocin H4, a bacteriocin from the halophilic archaeon Haloferax mediterranei R4

“…First, the amino-terminal n region is highly charged (ϩ6) and is very long (18 residues). Similar n regions have been found in the signal peptides of a halolysin (13) and of a xylanase from Streptomyces halstedii (27). Second, the polar c region is atypically long at 14 residues but begins with a glycine residue (residue 33), which is typical in prokaryotes (11).…”

The sequence of a subtilisin‐type protease (aerolysin) from the hyperthermophilic archaeum Pyrobaculum aerophilum reveals sites important to thermostability

“…Similarity to other serine proteases was much weaker. In particular, the P. aerophiium sequence showed weak homology to aqualysin I, produced by ' I : aquaticus (Terada et al, 1990), and halolysin, a serine protease from a moderately thermophilic (60 "C) and halophilic archaeum (Kamekura et al, 1992). Neutral proteases such as thermolysin (Pauptit et al, 1988), despite their structural similarity, were not recovered by BLAST or Predictprotein and were not included in the alignment.…”

“…Pairwise similarity scores (percentile) are listed at the end of each sequence. AEROLYSIN, protease from P. aerophilurn; THERMITASE, thermitase from T. vulgaris (Meloun et al, 1985); Halolysin, halolysin from an unnamed halophilic archaebacterium (Kamekura et al, 1992); SUBT. TA41, subtilisin from Antarctic B. subtilis strain TA41 (Davail et al, 1992); SUBT.…”

Characterization of halophilic bacteria from environmental samples from the brackish water of Pulicat Lake, India

“…Halophilic microorganisms are potential sources of enzymes uniquely adapted to activity at high salt concentrations with application in beverages, pharmaceutical and detergent industries (Kamekura et al 1992; Kobayashi et al 1994;Adams & Kelly 1995;Li et al 2002), leather industry (Birbir et al 1996) and food preservative industries (Ventosa et al 1995;Mellado et al 2003). However, no focused research has been undertaken.…”