1rl0: Difference between revisions

[[Image:1rl0.gif|left|200px]]<br /><applet load="1rl0" size="350" color="white" frame="true" align="right" spinBox="true"  

Ribosome inactivating proteins (RIPs) are plant proteins with enzymatic activity identified as rRNA N-glycosidase (EC 3.2.2.22), which cleaves the N-glycosidic bond of a specific adenine on the ricin/sarcin region of rRNA, thus causing inhibition of protein synthesis. They also depurinate extensively DNA and other polynucleotides. The three-dimensional structure of dianthin 30, a type 1 (single-chain) RIP of Dianthus caryophyllus (leaves), is now described at 1.4 angstroms, a resolution never achieved before for any RIP. The fold typical of RIPs is conserved, despite some differences in the loop regions. The general structure comparison by superimposed alpha-carbon (249 atoms) and the sequence alignment by structure for dianthin 30 and saporin-S6 give a root mean square deviation of 0.625 angstroms. Despite the differences reported for the biological activities of the two RIPs, their structures fit quite well and both show a protein segment containing strands beta7, beta8, and beta9 shorter than other RIPs. However, the surface electrostatic potential in the active site region neatly distinguishes dianthin 30 from saporin-S6. The possible relationship between the charge distribution and the behavior of the proteins toward different substrates is discussed.

1RL0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Dianthus_caryophyllus Dianthus caryophyllus]. Active as [http://en.wikipedia.org/wiki/rRNA_N-glycosylase rRNA N-glycosylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.22 3.2.2.22] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RL0 OCA].  

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