Backbone resonance assignments of the C-terminal thioesterase domain of tyrocidine synthetase C.

Natural macrocyclic peptides produced by microorganisms serve as valuable resources for therapeutic compounds, including antibiotics, anticancer agents, and immune suppressive agents. Nonribosomal peptide synthetases (NRPSs) are responsible for the biosynthesis of macrocyclic peptides. NRPSs are large multimodular enzymes, and each module recognizes and incorporates one specific amino acid into the polypeptide product.

A land plant-specific VPS13 mediates polarized vesicle trafficking in germinating pollen.

Pollen has an extraordinary ability to convert from a dry state to an extremely rapidly growing state. During pollination, pollen receives water and Ca from the contacting pistil, which will be a directional cue for pollen tube germination. The subsequent rapid activation of directional vesicular transport must support the pollen tube growth, but the molecular mechanism leading to this process is largely unknown.

Direct evidence for a deprotonated lysine serving as a H-bond "acceptor" in a photoreceptor protein.

Deprotonation or suppression of the pa of the amino group of a lysine sidechain is a widely recognized phenomenon whereby the sidechain amino group transiently can act as a nucleophile at the active site of enzymatic reactions. However, a deprotonated lysine and its molecular interactions have not been directly experimentally detected. Here, we demonstrate a deprotonated lysine stably serving as an "acceptor" in a H-bond between the photosensor protein RcaE and its chromophore.

Deep imaging reveals dynamics and signaling in one-to-one pollen tube guidance.

In the pistil of flowering plants, each ovule usually associates with a single pollen tube for fertilization. This one-to-one pollen tube guidance, which contributes to polyspermy blocking and efficient seed production, is largely different from animal chemotaxis of many sperms to one egg. However, the functional mechanisms underlying the directional cues and polytubey blocks in the depths of the pistil remain unknown.