3S86

Crystal Structure of TM0159 with bound IMP

Summary for 3S86

• Entry DOI: 10.2210/pdb3s86/pdb
• Related: 1vp2
• Descriptor: Nucleoside-triphosphatase, INOSINIC ACID, SULFATE ION, ... (4 entities in total)
• Functional Keywords: long twisted beta strand covered by two lobes, non-canonical nucleoside triphosphatase, hydrolase
• Biological source: Thermotoga maritima
• Total number of polymer chains: 4
• Total formula weight: 97115.23

Authors

Sommerhalter, M.,Smith, C.,Awwad, K.,Desai, A. (deposition date: 2011-05-27, release date: 2012-06-06, Last modification date: 2024-02-28)

Primary citation

Awwad, K.,Desai, A.,Smith, C.,Sommerhalter, M.
Structural and functional characterization of a noncanonical nucleoside triphosphate pyrophosphatase from Thermotoga maritima.
Acta Crystallogr.,Sect.D, 69:184-193, 2013

PubMed Abstract: The hyperthermophilic bacterium Thermotoga maritima has a noncanonical nucleoside triphosphatase that catalyzes the conversion of inosine triphosphate (ITP), deoxyinosine triphosphate (dITP) and xanthosine triphosphate (XTP) into inosine monophosphate (IMP), deoxyinosine monophosphate (IMP) and xanthosine monophosphate (XMP), respectively. The k(cat)/K(m) values determined at 323 and 353 K fall between 1.31 × 10(4) and 7.80 × 10(4) M(-1) s(-1). ITP and dITP are slightly preferred over XTP. Activity towards canonical nucleoside triphosphates (ATP and GTP) was not detected. The enzyme has an absolute requirement for Mg(2+) as a cofactor and has a preference for alkaline conditions. A protein X-ray structure of the enzyme with bound IMP was obtained at 2.15 Å resolution. The active site houses a well conserved network of residues that are critical for substrate recognition and catalysis. The crystal structure shows a tetramer with two possible dimer interfaces. One of these interfaces strongly resembles the dimer interface that is found in the structures of other noncanonical nucleoside pyrophosphatases from human (human ITPase) and archaea (Mj0226 and PhNTPase).

PubMed: 23385455
DOI: 10.1107/S0907444912044630

Experimental method

X-RAY DIFFRACTION (2.15 Å)