Structure of Thermococcus litoralis trans-3-hydroxy-l-proline dehydratase in the free and substrate-complexed form

2019 ◽  
Vol 516 (1) ◽  
pp. 189-195 ◽  
Author(s):  
Davide M. Ferraris ◽  
Riccardo Miggiano ◽  
Seiya Watanabe ◽  
Menico Rizzi
Author(s):  
Ryushi Kawakami ◽  
Chinatsu Kinoshita ◽  
Tomoki Kawase ◽  
Mikio Sato ◽  
Junji Hayashi ◽  
...  

Abstract The amino acid sequence of the OCC_10945 gene product from the hyperthermophilic archaeon Thermococcus litoralis DSM5473, originally annotated as γ-aminobutyrate aminotransferase, is highly similar to that of the uncharacterized pyridoxal 5ʹ-phosphate (PLP)-dependent amino acid racemase from Pyrococcus horikoshii. The OCC_10945 enzyme was successfully overexpressed in Escherichia coli by co-expression with a chaperone protein. The purified enzyme demonstrated PLP-dependent amino acid racemase activity primarily toward Met and Leu. Although PLP contributed to enzyme stability, it only loosely bound to this enzyme. Enzyme activity was strongly inhibited by several metal ions, including Co2+ and Zn2+, and non-substrate amino acids such as l-Arg and l-Lys. These results suggest that the underlying PLP-binding and substrate recognition mechanisms in this enzyme are significantly different from those of the other archaeal and bacterial amino acid racemases. This is the first description of a novel PLP-dependent amino acid racemase with moderate substrate specificity in hyperthermophilic archaea.


2010 ◽  
Vol 24 (3-4) ◽  
pp. 349-353 ◽  
Author(s):  
Olga I. Povarova ◽  
Olga V. Stepanenko ◽  
Anna I. Sulatskaya ◽  
Irina M. Kuznetsova ◽  
Konstantin K. Turoverov ◽  
...  

Fluorescence and circular dichroism in far-UV region were used to study the stability of trehalose/maltose binding protein (TMBP) from hyper thermophilic archaeonThermococcus litoralisand its complex with glucose (TMBP/Glc). The evaluation of difference between free energy of native and unfolded state for TMBP and TMBP/Glc showed that both of them are several times higher than that of proteins from mesophilic organisms. Due to the high stability and innate ability to bind glucose this protein is a good candidate as a sensitive element in biosensor systems for sugar control.


1994 ◽  
Vol 116 (15) ◽  
pp. 6841-6849 ◽  
Author(s):  
Antonio Donaire ◽  
Carol M. Gorst ◽  
Z. H. Zhou ◽  
Michael W. W. Adams ◽  
Gerd N. La Mar

1996 ◽  
Vol 178 (16) ◽  
pp. 4773-4777 ◽  
Author(s):  
K B Xavier ◽  
L O Martins ◽  
R Peist ◽  
M Kossmann ◽  
W Boos ◽  
...  

1998 ◽  
Vol 180 (3) ◽  
pp. 680-689 ◽  
Author(s):  
Reinhold Horlacher ◽  
Karina B. Xavier ◽  
Helena Santos ◽  
Jocelyne DiRuggiero ◽  
Marina Kossmann ◽  
...  

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.


2007 ◽  
Vol 189 (24) ◽  
pp. 8901-8913 ◽  
Author(s):  
Antje Labes ◽  
Peter Schönheit

ABSTRACT The hyperthermophilic archaeon Archaeoglobus fulgidus strain 7324 has been shown to grow on starch and sulfate and thus represents the first sulfate reducer able to degrade polymeric sugars. The enzymes involved in starch degradation to glucose 6-phosphate were studied. In extracts of starch-grown cells the activities of the classical starch degradation enzymes, α-amylase and amylopullulanase, could not be detected. Instead, evidence is presented here that A. fulgidus utilizes an unusual pathway of starch degradation involving cyclodextrins as intermediates. The pathway comprises the combined action of an extracellular cyclodextrin glucanotransferase (CGTase) converting starch to cyclodextrins and the intracellular conversion of cyclodextrins to glucose 6-phosphate via cyclodextrinase (CDase), maltodextrin phosphorylase (Mal-P), and phosphoglucomutase (PGM). These enzymes, which are all induced after growth on starch, were characterized. CGTase catalyzed the conversion of starch to mainly β-cyclodextrin. The gene encoding CGTase was cloned and sequenced and showed highest similarity to a glucanotransferase from Thermococcus litoralis. After transport of the cyclodextrins into the cell by a transport system to be defined, these molecules are linearized via a CDase, catalyzing exclusively the ring opening of the cyclodextrins to the respective maltooligodextrins. These are degraded by a Mal-P to glucose 1-phosphate. Finally, PGM catalyzes the conversion of glucose 1-phosphate to glucose 6-phosphate, which is further degraded to pyruvate via the modified Embden-Meyerhof pathway.


Sign in / Sign up

Export Citation Format

Share Document