Organization of the gene for batroxobin, a thrombin-like snake venom enzyme. Homology with the trypsin/kallikrein gene family.

N Itoh,N Tanaka,I Funakoshi,T Kawasaki,S Mihashi,I Yamashina

doi:10.1016/s0021-9258(18)68544-8

N Itoh, N Tanaka + Show 4 more

Open Access

https://doi.org/10.1016/s0021-9258(18)68544-8

Copy DOI

Abstract

We have isolated and analyzed the gene for batroxobin, a thrombin-like snake venom enzyme. Three overlapping DNA segments containing the entire batroxobin gene were identified. Sequence analysis revealed that the batroxobin gene spans 8 kilobase pairs and contains five exons. Mature batroxobin is encoded by four separate exons, 2 to 5. The catalytic residues of batroxobin, His-41, Asp-86, and Ser-178, are encoded by separate exons, exons 2, 3, and 5, respectively. The exon/intron organization of the batroxobin gene is different from that of the prothrombin gene but very similar to those of the trypsin and kallikrein genes. These results indicate that batroxobin is not a member of the prothrombin family but one of the trypsin/kallikrein family. The snake venom gland is assumed to originate from the submaxillary gland. Therefore, batroxobin is expected to be a member of the glandular kallikrein family.

Highlights

From the $Division of Biological Engineering, Kyoto Sangyo University, Kyoto 603, the §Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Kyoto University, Kyoto606, and the YKoganei Research Laboratory, Tobishi Pharmaceutical Co., Koganei, Tokyo 184,Japan
We have isolated and analyzed the gene for batrox- that members of the serine protease gene family can be obin,athrombin-like snake venomenzyme.Three classified into several subfamilies. These results provide us overlapping DNA segments containing the entire ba- with new clues as to the evolutionary development of the troxobin gene were identified
Sequence analysis re- genes [3]. vealed that the batroxobingene spans 8 kilobase pairs The elucidation of the gene organization for a thrombinand containsfive exons

Summary

THEJOURNAOLF BIOLOGICACLHEMISTRY

Vol 263, No 16, Issue of June 5,pp. 7628-7631, 1988 Printed in U.S.A. Nobuyuki Itoh$, Nobuhiro Tanakag, Ikuo FunakoshiQ, Toshisuke Kawasaki$, Susumu Mihashill, and Ikuo Yamashinag. The nucleotease regions of these genes indicate that different domains of the protease regions are encoded by separate exons and tide sequences of the deleted DNA inserts were determined by the dideoxy method [8]. Isolation of the Batroxobin Gem-The 32P-labeledbatroxobin cDNA wasused to screen a genomic DNAlibrary derived from B. atrox, moojeni venom glands. Eight positive clones were isolated, and the nucleotide sequences of the DNA inserts were determined by the unidirectional deletion method followed by the dideoxy method. 1 and 2) and provided independent confirmation of the cDNA sequence determined previously [2].The polyadenylation site residue of the batroxobin cDNA [2] was at the3' end of exon 5 (Fig. 2).

MetVal IeuIle

Several kinds of proteases from the venomof different

Batroxobin Trypsin Kallikrein