Primers used in this study.

<p>Capital letters stand for nucleotides from chromosomal sequences. The recognition sites for restriction enzymes are underlined.</p

Zeaxanthin-monoglycoside and zeaxanthin-diglycoside could be synthesized in <i>E. coli</i> when seven <i>C. sakazakii</i> genes were expressed.

<p>A. TLC analysis of carotenoids EC1 and EC2 produced by DH5α/pWSK29-<i>EiZYIBX</i>. B. UV-visible spectra of purified EC1 and EC2. C. ESI/MS analysis of purified EC1. D. ESI/MS analysis of purified EC2. E. HPLC analysis of the hexose hydrolyzed from EC1.</p

Lycopene and β-carotene could be synthesized in <i>E. coli</i> when <i>C. sakazakii</i> genes <i>crtE</i>, <i>idi</i>, <i>crtI</i> and <i>crtB</i> were expressed with or without <i>crtY</i>, respectively.

<p>A. TLC analysis of carotenoids EC1 and EC2 produced by DH5α/pWSK29-<i>EiIB</i> and DH5α/pWSK29-<i>EiYIB</i>, respectively. B. UV-visible spectra of purified EC1 and EC2. C. HPLC spectra of purified EC1 and EC2.</p

Plasmids and strains used in this study.

<p>Plasmids and strains used in this study.</p

The proposed pathway of carotenoid biosynthesis in <i>C. sakazakii</i> BAA894.

<p>The names used in this article for each molecule were listed on the right.</p

Analysis of yellow pigments produced by <i>C. sakazakii</i> BAA894.

<p>A. TLC analysis of yellow pigments CS1 and CS2 produced by <i>C. sakazakii</i> BAA894. B. UV-visible spectra of purified CS1 and CS2. C. ESI/MS analysis of the purified CS1. E. ESI/MS analysis of the purified CS2.</p

<i>C. sakazakii</i> gene <i>crtZ</i> is responsible for the biosynthesis of cryptoxanthin and zeaxanthin from β-carotene.

<p>A. TLC analysis of carotenoids EC3 and EC4 produced by DH5α/pWSK29-<i>EiZYIB</i>. B. UV-visible spectra of purified EC3 and EC4. C. ESI/MS of purified EC3. D. ESI/MS of purified EC4.</p

Organization of carotenoid biosynthesis genes in <i>C. sakazakii</i>.

<p>Direction of transcription is indicated by arrows. ORF numbers of the corresponding genes, and identities of the corresponding proteins in <i>C. sakazakii</i> strains ES5 and BAA894 are listed. Only the gene <i>idi</i> was annotated in the genome of <i>C. sakazakii</i> BAA894.</p

Asymmetric Structure of the Dimerization Domain of PhoR, a Sensor Kinase Important for the Virulence of Mycobacterium tuberculosis

The PhoP–PhoR two-component system is essential for the virulence of Mycobacterium tuberculosis (<i>Mtb</i>) and therefore represents a potential target for developing novel antituberculosis therapies. However, little is known about the mechanism by which this two-component system regulates the virulence. In this study, we demonstrated that a <i>phoR</i> mutant <i>Mtb</i> strain has phenotypes similar to those of a <i>phoP</i> mutant, suggesting that PhoP and PhoR work in the same pathway to regulate <i>Mtb</i> virulence. We determined the structure of the dimerization and histidine phosphotransfer (DHp) domain of PhoR to a 1.9 Å resolution. The structure revealed that the DHp domain is a dimer. Each subunit consists of two antiparallel α helices connected by a loop of five residues. The two subunits of the dimer fold into a four-helical bundle with a continuous hydrophobic core. The topology of the four-helical bundle is identical to the histidine kinases that are known to have a cis-autophosphorylation mechanism, suggesting that PhoR is likely to autophosphorylate in cis. The dimer is asymmetric, with one subunit having a greater bending angle than the other at the highly conserved proline residue five-residues downstream of the phosphorylation site histidine. This structural asymmetry of the dimer suggests the flexibility of the PhoR DHp domain, which is likely to be important for the signal transduction mechanism in controlling the autophosphorylation and phosphotransfer reactions and communicating with the upstream structure

<i>Ring1b</i> mutants lack almost all head cartilage elements.

<p>Lateral view of WT and <i>ring1b</i> live embryos at 72 hpf (A, B). Alcian-Blue stained head cartilages of WT (C, E, G and H) and <i>ring1b</i> (D, F, H and J) mutants at the indicated developmental points, ventral views. The paired trabeculae have elongated and fused posteriorly in WT embryos at 56 hpf (E) and by 72 hpf the elaborate cartilagenous skeleton of the head has been established (I). In contrast, no cartilage is visible in <i>ring1b</i> mutants except for two minute cartilage deposits at 72 hpf <i>ring1b</i> mutants (J: arrowheads). ch: ceratohyal; ep: ethmoid plate; hys: hyosymplectic; m: Meckel’s cartilage; pc: parachordal, pq: palatoquadrate; tc: trabeculae.</p