Myxococcus xanthus truncated globin HbO: in silico analysis and functional characterization

Area of Science:

• Microbiology
• Biochemistry
• Molecular Biology

Background:

• Truncated globins are shorter variants of full-length globins.
• Known bacterial globins play roles in virulence, nitrogen fixation, and photosynthesis.
• Myxococcus xanthus is an obligate aerobe with a multicellular stage experiencing oxygen limitation.

Purpose of the Study:

• Investigate the role of a truncated globin in Myxococcus xanthus.
• Characterize the function and expression of the identified truncated globin (HbO).

Main Methods:

• Bioinformatic sequence analysis of the putative truncated globin (HbO).
• Gene cloning and expression of Mx-HbO in E. coli.
• Spectroscopic analysis to confirm globin functionality.
• Gene expression analysis under varying aeration conditions.

Main Results:

• Mx-HbO adopts a characteristic truncated globin fold.
• Expression in E. coli resulted in a functional globin with improved host growth and higher cell density.
• Mx-hbO transcript levels increased threefold under low aeration compared to high aeration.
• The globin's expression is induced by oxygen-deprived conditions.

Conclusions:

• Mx-HbO is a functional truncated globin.
• This globin likely facilitates growth in oxygen-deprived environments, such as the dense centers of M. xanthus swarms.