Key Role of Two Terminal Domains in the Bidirectional Polymerization of FtsA Protein

• Published in: The Journal of biological chemistry Vol. 287; no. 10; pp. 7756 - 7765
• Main Authors: Krupka, Marcin, Rivas, Germán, Rico, Ana Isabel, Vicente, Miguel
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 02.03.2012; American Society for Biochemistry and Molecular Biology
• Subjects: Adenosine Triphosphate - chemistry; Adenosine Triphosphate - metabolism; Bacterial Genetics; Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; Cell Division; FtsA; Microbiology; Polymerization; Protein Assembly; Protein Domains; Protein Multimerization - physiology; Protein Structure, Tertiary; Streptococcus; Streptococcus pneumoniae; Streptococcus pneumoniae - chemistry; Streptococcus pneumoniae - metabolism; Streptococcus; Cell Division; Protein Domains; Polymerization; Bacterial Genetics; FtsA; Protein Assembly; Streptococcus pneumoniae
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M111.311563

The effect of two different truncations involving either the 1C domain or the simultaneous absence of the S12–13 β-strands of the FtsA protein from Streptococcus pneumoniae, located at opposite terminal sides in the molecular structure, suggests that they are essential for ATP-dependent polymerization. These two truncated proteins are not able to polymerize themselves but can be incorporated to some extent into the FtsA+ polymers during the assembling process. Consequently, they block the growth of the FtsA+ polymers and slow down the polymerization rate. The combined action of the two truncated proteins produces an additive effect on the inhibition of FtsA+ polymerization, indicating that each truncation affects a different interaction site within the FtsA molecule. Essential divisome protein FtsA polymers may be formed by a head-to-tail mechanism. Deletion of domain 1C or region S12–13, located at opposing ends, synergistically blocks polymerization. FtsA polymerization proceeds head to tail and is bidirectional. These domains, essential for FtsA polymerization, are among those that differ most from other members of the actin-MreB-ParM family.