Wheat is one of the most important food crops for human consumption globally. Breeders are making efforts to produce high yielding modern varieties, however, the productivity of a particular cultivar can be severely restricted by its susceptibility to diseases, such as stripe rust, caused by the fungus Puccinia striiformis f. sp. tritici (Pst). To overcome this problem, disease resistance genes from wheat wild relatives can be introgressed into elite cultivars. Yr15, is a wild emmer wheat (Triticum dicoccoides) gene, known to carry high resistance to a wide range of Pst isolates. Comparative genomics, chromosome walking, BAC libraries (wild emmer and bread wheat), whole genome assemblies, EMS mutagenesis and transgenic approaches enabled us to clone Yr15 and validate its function. Analysis of the protein encoded by Yr15 revealed that it has a putative kinase-pseudokinase structure, designated as Wheat Tandem Kinase 1 (WTK1) (Klymiuk et al. 2018; Nature Communications). The available reference wheat genomes, Chinese Spring, Svevo and Zavitan, have paved the way for the discovery of a unique protein family. WTK1 orthologs and paralogs are found in all group 1 and 6 wheat chromosomes. The exon-intron structure of orthologues copies is similar to that of Wtk1 from Yr15 donor accession G25, but differ in numerous SNPs and indels that cause changes in reading frames. Although exon-intron structure of the paralogues copies (6A, 6B and 6D) is similar to Wtk1, the total number of exons was increased from six to seven due to the split of exon 4 into two. The unique protein architecture of WTK1 was found in 92 putative proteins across the plant kingdom, including the barley RPG1 and a candidate for Un8, suggesting that they are members of a distinct family of plant proteins, termed here tandem kinase-pseudokinases (TKPs). We found that 175 out of 184 kinase/pseudokinase domains of these TKPs were associated with receptor-like kinases (RLKs), suggesting that TKPs are involved in plant defense mechanisms. The decoy role can be proposed as one of the potential model of function of the pseudokinases of TKP family members in immune response. A further phylogenetic analysis indicated that TKP family members originated from either gene duplication or gene fusion events, suggesting a polyphyletic origin of the TKPs. The presence of kinasepseudokinase structure in plant TKPs and animal Janus kinases (JAKs), is suggesting convergent molecular evolution of proteins involved in immunity in both of the kingdoms.