Bacterial Type III Secretion System Effector Proteins are Distinct between Plant Symbiotic, Plant Pathogenic and Animal Pathogenic Bacteria

Abstract

Type III secretion system (T3SS) effector protein is a part of bacterial secretion systems. T3SS exists in the pathogenic and symbiotic bacteria. How the T3SS effector proteins in these two classes differ from each other should be interesting. In this paper, we successfully discriminated T3SS effector proteins between plant pathogenic, animal pathogenic and plant symbiotic bacteria based on feature vectors inferred computationally by Yahara et al. only from amino acid sequences. This suggests that these three classes of bacteria employ distinct T3SS effector proteins. We also hypothesized that the feature vector proposed by Yahara et al. represents protein structure, possibly protein folds defined in Structural Classification of Proteins (SCOP) database.

Nodulation outer proteins: double-edged swords of symbiotic rhizobia

“…Compared with T3 effectors from pathogenic bacteria, Nops seem to possess certain conserved features. Rhizobial proteins related to the T3SS could be clearly discriminated from those of plant pathogenic bacteria when amino acid sequences were analysed using statistical and machine learning methods [41,42]. Nevertheless, Nops known to be secreted by rhizobial T3SS can also be secreted through the T3SS of P. syringae [28,43,44], indicating that N-terminal secretion signals are interchangeable among symbiotic and pathogenic bacteria.…”