1x0t

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spinqualitylabelsall models 1x0t, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of ribonuclease P protein Ph1601p from Pyrococcus horikoshii OT3

Overview

Ribonuclease P (RNase P) is a ribonucleoprotein complex involved in the, removal of 5' leader sequences from tRNA precursors (pre-tRNA). The human, protein Rpp21 is essential for human RNase P activity in tRNA processing, in vitro. The crystal structure of Ph1601p from the hyperthermophilic, archaeon Pyrococcus horikoshii OT3, the archaeal homologue of Rpp21, was, determined using the multiple anomalous dispersion (MAD) method with the, aid of anomalous scattering in zinc and selenium at 1.6 A resolution., Ph1601p comprises an N-terminal domain (residues 1-55), a central linker, domain (residues 56-79), and a C-terminal domain (residues 80-120), forming an L-shaped structure. The N-terminal domain consists of two long, alpha-helices, while the central and C-terminal domains fold in a zinc, ribbon domain. The electrostatic potential representation indicates the, presence of positively charged clusters along the L arms, suggesting a, possible role in RNA binding. A single zinc ion binds the well-ordered, binding site that consists of four Cys residues (Cys68, Cys71, Cys97, and, Cys100) and appears to stabilize the relative positions of the N- and, C-domains. Mutations of Cys68 and Cys71 or Cys97 and Cys100 to Ser, destabilize the protein structure, which results in inactivation of the, RNase P activity. In addition, site-directed mutagenesis suggests that, Lys69 at the central loop and Arg86 and Arg105 at the zinc ribbon domain, are strongly involved in the functional activity, while Arg22, Tyr44, Arg65, and Arg84 play a modest role in the activity.

About this Structure

1X0T is a Single protein structure of sequence from Pyrococcus horikoshii with ZN as ligand. Active as Ribonuclease P, with EC number 3.1.26.5 Full crystallographic information is available from OCA.

Reference

Crystal structure of a ribonuclease P protein Ph1601p from Pyrococcus horikoshii OT3: an archaeal homologue of human nuclear ribonuclease P protein Rpp21., Kakuta Y, Ishimatsu I, Numata T, Kimura K, Yao M, Tanaka I, Kimura M, Biochemistry. 2005 Sep 13;44(36):12086-93. PMID:16142906

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