1V8O

Crystal Structure of PAE2754 from Pyrobaculum aerophilum

Summary for 1V8O

• Entry DOI: 10.2210/pdb1v8o/pdb
• Related: 1V8P
• Descriptor: hypothetical protein PAE2754, CHLORIDE ION (3 entities in total)
• Functional Keywords: pin-domain, semet substituted, structural genomics, unknown function
• Biological source: Pyrobaculum aerophilum
• Total number of polymer chains: 8
• Total formula weight: 145608.04

Authors

Arcus, V.L.,Backbro, K.,Roos, A.,Daniel, E.L.,Baker, E.N. (deposition date: 2004-01-12, release date: 2004-02-10, Last modification date: 2024-10-16)

Primary citation

Arcus, V.L.,Backbro, K.,Roos, A.,Daniel, E.L.,Baker, E.N.
Distant structural homology leads to the functional characterization of an archaeal PIN domain as an exonuclease
J.Biol.Chem., 279:16471-16478, 2004

PubMed Abstract: Genome sequencing projects have focused attention on the problem of discovering the functions of protein domains that are widely distributed throughout living species but which are, as yet, largely uncharacterized. One such example is the PIN domain, found in eukaryotes, bacteria, and Archaea, and with suggested roles in signaling, RNase editing, and/or nucleotide binding. The first reported crystal structure of a PIN domain (open reading frame PAE2754, derived from the crenarchaeon, Pyrobaculum aerophilum) has been determined to 2.5 A resolution and is presented here. Mapping conserved residues from a multiple sequence alignment onto the structure identifies a putative active site. The discovery of distant structural homology with several exonucleases, including T4 phage RNase H and flap endonuclease (FEN1), further suggests a likely function for PIN domains as Mg2+-dependent exonucleases, a hypothesis that we have confirmed in vitro. The tetrameric structure of PAE2754, with the active sites inside a tunnel, suggests a mechanism for selective cleavage of single-stranded overhangs or flap structures. These results indicate likely DNA or RNA editing roles for prokaryotic PIN domains, which are strikingly numerous in thermophiles, and in organisms such as Mycobacterium tuberculosis. They also support previous hypotheses that eukaryotic PIN domains participate in RNAi and nonsense-mediated RNA degradation.

PubMed: 14734548
DOI: 10.1074/jbc.M313833200

Experimental method

X-RAY DIFFRACTION (2.8 Å)