PMID- 29160840
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20200929
IS  - 2075-1729 (Print)
IS  - 2075-1729 (Electronic)
IS  - 2075-1729 (Linking)
VI  - 7
IP  - 4
DP  - 2017 Nov 21
TI  - Cloning and Molecular Characterization of an Alpha-Glucosidase (MalH) from the 
      Halophilic Archaeon Haloquadratum walsbyi.
LID - 10.3390/life7040046 [doi]
LID - 46
AB  - We report the heterologous expression and molecular characterization of the first 
      extremely halophilic alpha-glucosidase (EC 3.2.1.20) from the archaeon 
      Haloquadratum walsbyi. A 2349 bp region (Hqrw_2071) from the Hqr. walsbyi C23 
      annotated genome was PCR-amplified and the resulting amplicon ligated into 
      plasmid pET28b(+), expressed in E. coli Rosetta cells, and the resulting protein 
      purified by Ni-NTA affinity chromatography. The recombinant protein showed an 
      estimated molecular mass of 87 kDa, consistent with the expected value of the 
      annotated protein, and an optimal activity for the hydrolysis of alpha-PNPG was 
      detected at 40  degrees C, and at pH 6.0. Enzyme activity values were the highest in the 
      presence of 3 M NaCl or 3-4 M KCl. However, specific activity values were 
      two-fold higher in the presence of 3-4 M KCl when compared to NaCl suggesting a 
      cytoplasmic localization. Phylogenetic analyses, with respect to other 
      alpha-glucosidases from members of the class Halobacteria, showed that the Hqr. 
      walsbyi MalH was most similar (up to 41%) to alpha-glucosidases and 
      alpha-xylosidases of Halorubrum. Moreover, computational analyses for the 
      detection of functional domains, active and catalytic sites, as well as 3D 
      structural predictions revealed a close relationship with an E. coli YicI-like 
      alpha-xylosidase of the GH31 family. However, the purified enzyme did not show 
      alpha-xylosidase activity. This narrower substrate range indicates a discrepancy 
      with annotations from different databases and the possibility of specific 
      substrate adaptations of halophilic glucosidases due to high salinity. To our 
      knowledge, this is the first report on the characterization of an 
      alpha-glucosidase from the halophilic Archaea, which could serve as a new model 
      to gain insights into carbon metabolism in this understudied microbial group.
FAU - Cuebas-Irizarry, Mara F
AU  - Cuebas-Irizarry MF
AD  - Biology Department, Box 9000, University of Puerto Rico, Mayaguez, PR 00681, USA. 
      mara.cuebas@upr.edu.
FAU - Irizarry-Caro, Ricardo A
AU  - Irizarry-Caro RA
AD  - Department of Immunology, University of Texas Southwestern Medical Center, 
      Dallas, TX 75390, USA. ricardo.irizarry-caro@utsouthwestern.edu.
FAU - Lopez-Morales, Carol
AU  - Lopez-Morales C
AD  - Biology Department, Box 9000, University of Puerto Rico, Mayaguez, PR 00681, USA. 
      c_lopez_pr@yahoo.com.
FAU - Badillo-Rivera, Keyla M
AU  - Badillo-Rivera KM
AD  - Genetics Department, School of Medicine, Stanford University, Stanford, CA 94305, 
      USA. kbadillo@stanford.edu.
FAU - Rodriguez-Minguela, Carlos M
AU  - Rodriguez-Minguela CM
AD  - Biology Department, Box 9000, University of Puerto Rico, Mayaguez, PR 00681, USA. 
      carlos.rodriguez66@upr.edu.
FAU - Montalvo-Rodriguez, Rafael
AU  - Montalvo-Rodriguez R
AD  - Biology Department, Box 9000, University of Puerto Rico, Mayaguez, PR 00681, USA. 
      rafael.montalvo@upr.edu.
LA  - eng
PT  - Journal Article
DEP - 20171121
PL  - Switzerland
TA  - Life (Basel)
JT  - Life (Basel, Switzerland)
JID - 101580444
PMC - PMC5745559
OTO - NOTNLM
OT  - Haloquadratum
OT  - alpha-glucosidase
OT  - halophilic Archaea
COIS- The authors declare no conflict of interest.
EDAT- 2017/11/22 06:00
MHDA- 2017/11/22 06:01
PMCR- 2017/12/01
CRDT- 2017/11/22 06:00
PHST- 2017/08/31 00:00 [received]
PHST- 2017/11/15 00:00 [revised]
PHST- 2017/11/18 00:00 [accepted]
PHST- 2017/11/22 06:00 [entrez]
PHST- 2017/11/22 06:00 [pubmed]
PHST- 2017/11/22 06:01 [medline]
PHST- 2017/12/01 00:00 [pmc-release]
AID - life7040046 [pii]
AID - life-07-00046 [pii]
AID - 10.3390/life7040046 [doi]
PST - epublish
SO  - Life (Basel). 2017 Nov 21;7(4):46. doi: 10.3390/life7040046.