title: Phylogenetic analysis of STK gene family and Usp domain in maize.
abstract: Serine and threonine kinase STK1 and STK2 play an important regulatory role in the process of pollen development in maize. Six homologous sequences which were similar with STK1 and STK2 having more than 80 % similarity were found at NCBI, and they all belong to STK gene family. Phylogenetic analysis showed that STK family in maize might belong to RLK family. In STK family, gene duplication event was occurred during evolutionary process, and experienced purifying selection after gene duplication and the time of gene duplication was about 12 million years ago. The domains of STK family belongs to single transmembrane protein, which have intracellular conserved kinase catalytic domain and extracellular receptor domain on N-terminal. The evolution of intracellular selection was faster than extracellular selection, and positive selection or weak purifying selection play an important role. Analyzing its unique Usp domain we found that it was located between sensor domain at N-terminal and catalytic domain at C-terminal, which belongs to hydrophobic protein with several phosphorylation sites, acting on serine and threonine protein phosphorylation. The kinship of Usp domain in STK family was close to 35-like protein containing U-box domain, predicting that they might belong to the same family with a similar structure and function, so that we can predict the function of Usp domain in STK family.
authors.affiliation: Biotechnology and Bioscience College, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhou
authors.forename: Mingxia
authors.initials: M
authors.lastname: Fan
authors.forename: Muhammad
authors.initials: M
authors.lastname: Irfan
authors.forename: He
authors.initials: H
authors.lastname: Wang
authors.forename: Dongxu
authors.initials: D
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Chunyu
authors.initials: C
authors.lastname: Zhang
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
mesh_terms: D020440:Gene Duplication; D005810:Multigene Family; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics*; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D003313:Zea mays / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics
chemical_list: D010940:Plant Proteins; D017346:Protein Serine-Threonine Kinases