AI Article Synopsis
- The PH1527 gene from Pyrococcus horikoshii encodes a protein called PhTET2, which is similar to endoglucanases and M42 peptidases, forming stable dodecameric complexes.
- PhTET2 acts as an aminopeptidase, favoring leucine as its starting amino acid, but can also cleave various polypeptide substrates unspecifically.
- This enzyme is heat-stable, with peak activity near 100°C and demonstrates unique inhibition and activation properties with specific metal ions and inhibitors.
Article Abstract
Pyrococcus horikoshii open reading frame PH1527 encodes a 39014 Da protein that shares about 30% identity with endoglucanases and members of the M42 peptidase family. Analytical ultracentrifugation and electron microscopy studies showed that the purified recombinant protein forms stable, large dodecameric complexes with a tetrahedral shape similar to the one described for DAP, a deblocking aminopeptidase that was characterized in the same organism. The two related proteins were named PhTET1 (for DAP) and PhTET2 (for PH1527). The substrate specificity and the mode of action of the PhTET2 complex were studied in detail and compared to those of PhTET1 and other assigned M42 peptidases. When assayed with short chromogenic peptides, PhTET2 was found to be an aminopeptidase, with a clear preference for leucine as the N-terminal amino acid. However, the enzyme can cleave moderately long polypeptide substrates of various compositions in a fairly unspecific manner. The hydrolytic mechanism was found to be nonprocessive. The enzyme has neither carboxypeptidase nor endoproteolytic activities, and it is devoid of N-terminal deblocking activity. PhTET2 was inhibited in the presence of EDTA and bestatin, and cobalt was found to be an activating metal. The PhTET2 protein is a highly thermostable enzyme that displays optimal activity around 100 degrees C over a broad pH array.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/bi047736j | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Decoding Substrate Selectivity of an Archaeal RlmCD-like Methyltransferase Through Its Salient Traits.
Biochemistry
October 2024
Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India.
5-Methyluridine (mU) rRNA modifications frequently occur at U747 and U1939 ( numbering) in domains II and IV of the 23S rRNA in Gram-negative bacteria, with the help of -adenosyl-l-methionine (SAM)-dependent rRNA methyltransferases (MTases), RlmC and RlmD, respectively. In contrast, Gram-positive bacteria utilize a single SAM-dependent rRNA MTase, RlmCD, to modify both corresponding sites. Notably, certain archaea, specifically within the group, have been found to possess two genes encoding SAM-dependent archaeal (tRNA and rRNA) mU (ArmU) MTases.
View Article and Find Full Text PDFStructural and functional characterization of archaeal DIMT1 unveils distinct protein dynamics essential for efficient catalysis.
Structure
October 2024
Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India. Electronic address:
Dimethyladenosine transferase 1 (DIMT1), an ortholog of bacterial KsgA is a conserved protein that assists in ribosome biogenesis by modifying two successive adenosine bases near the 3' end of small subunit (SSU) rRNA. Although KsgA/DIMT1 proteins have been characterized in bacteria and eukaryotes, they are yet unexplored in archaea. Also, their dynamics are not well understood.
View Article and Find Full Text PDFHS-AFM single-molecule structural biology uncovers basis of transporter wanderlust kinetics.
Nat Struct Mol Biol
August 2024
Weill Cornell Medicine, Department of Anesthesiology, New York, NY, USA.
Article Synopsis
- The study investigates the amino acid transporter Glt from Pyrococcus horikoshii, highlighting its unpredictable activity patterns known as wanderlust kinetics.
- Researchers utilize high-speed atomic force microscopy to connect structural changes in the transporter to its functionality over time.
- Their methods allow for detailed analysis of individual molecules, revealing key structural states and suggesting a specific inward-facing state may hinder dynamic activity.
Distinct characteristics of putative archaeal 5-methylcytosine RNA methyltransferases unveil their substrate specificities and evolutionary ancestries.
J Biomol Struct Dyn
March 2024
Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India.
5-Methylcytosine methyltransferases (mC MTases) are known to be involved in the modification of RNA. Although these enzymes have been relatively well characterized in bacteria and eukarya, a complete understanding of the archaeal counterparts is lacking. In this study, the identification and characterization of archaeal RNA mC MTases were performed.
View Article and Find Full Text PDFThe rapid proximity labeling system PhastID identifies ATP6AP1 as an unconventional GEF for Rheb.
Cell Res
May 2024
MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Institute of Healthy Aging Research, Sun Yat-sen University, Guangzhou, Guangdong, China.
Rheb is a small G protein that functions as the direct activator of the mechanistic target of rapamycin complex 1 (mTORC1) to coordinate signaling cascades in response to nutrients and growth factors. Despite extensive studies, the guanine nucleotide exchange factor (GEF) that directly activates Rheb remains unclear, at least in part due to the dynamic and transient nature of protein-protein interactions (PPIs) that are the hallmarks of signal transduction. Here, we report the development of a rapid and robust proximity labeling system named Pyrococcus horikoshii biotin protein ligase (PhBPL)-assisted biotin identification (PhastID) and detail the insulin-stimulated changes in Rheb-proximity protein networks that were identified using PhastID.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!