(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Bacteria: NE > Proteobacteria: NE > Alphaproteobacteria: NE > Caulobacterales: NE > Caulobacteraceae: NE > Asticcacaulis: NE > Asticcacaulis benevestitus: NE > Asticcacaulis benevestitus DSM 16100 = ATCC BAA-896: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MKRRRGLVIGGAIATFVALALLYLQNDIHRDLLDPKIPFPVYQPPPAPDY AKMDAWHLNPALAKFYADPRKVDVFFIHATSFNGGKSWLGATGSNAAQED VHRIQLPNYAAPFGIMGNIYAPKYRQASLYTQLTLREDAREARQFAYRDV EAAFRVFLKKRQGGRGFVIVGIEQGGVLAERLIRDIVAPDPDLKQQLVAA YLLETLVPESQFGPQSPWLPACMSRQQTHCLVSYVSINSGRPDIALQVLQ KAVYWEGDELAGLGSAKGVCVNPLLGAASNEEVAARHSLGATNATGLEWG TEPPLSPRKVSAHCLRGLLFVDKPNSPSLRDDGTWEGQRKVNPYNLFYGD LQADIQARWQAYQALPVPAQP
Reference
Title: Sequential evolution of bacterial morphology by co-option of a developmental regulator Jiang C, Brown PJ, Ducret A, Brun YV Ref: Nature, 506:489, 2014 : PubMed
What mechanisms underlie the transitions responsible for the diverse shapes observed in the living world? Although bacteria exhibit a myriad of morphologies, the mechanisms responsible for the evolution of bacterial cell shape are not understood. We investigated morphological diversity in a group of bacteria that synthesize an appendage-like extension of the cell envelope called the stalk. The location and number of stalks varies among species, as exemplified by three distinct subcellular positions of stalks within a rod-shaped cell body: polar in the genus Caulobacter and subpolar or bilateral in the genus Asticcacaulis. Here we show that a developmental regulator of Caulobacter crescentus, SpmX, is co-opted in the genus Asticcacaulis to specify stalk synthesis either at the subpolar or bilateral positions. We also show that stepwise evolution of a specific region of SpmX led to the gain of a new function and localization of this protein, which drove the sequential transition in stalk positioning. Our results indicate that changes in protein function, co-option and modularity are key elements in the evolution of bacterial morphology. Therefore, similar evolutionary principles of morphological transitions apply to both single-celled prokaryotes and multicellular eukaryotes.
