Structure of the formin INF2 bound to the barbed end of F-actin.

Molecular mechanism of actin filament elongation by formins.

12 mM HEPES pH 7.1, 100 mM KCl, 2.1 mM MgCl2, 1 mM EGTA, 1 mM TCEP, 0.2 mM ATP

Alpha actin was purified from rabbit skeletal muscle. INF2 was purified from E. coli. Actin filaments were co-polymerized in the presence of the formin INF2 prior to cryo-EM grid preparation.
Complex of the formin INF2 dimer that binds to the actin subunits at the barbed end of actin filaments.

Complex of the actin subunits that form the barbed end of actin filaments.

This dimer is composed of the FH2 domain of the formin INF2.

300 kV Titan Krios G3 microscope (Thermo Fisher Scientific).

Rabbit skeletal alpha actin purified from frozen rabbit muscle acetone powder.

INF2 FH1FH2C nonCAAX isoform was recombinantly expressed in E. coli BL21 Star pRARE cells and purified. This compound consists of the formin homology 1 and 2 domains, as well as the C-terminal region of the human formin INF2 isoform nonCAAX.

DEDETTALVCDNGSGLVKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEAQSKRGILTLKYPIE(HIC)GII
TNWDDMEKIWHHTFYNELRVAPEEHPTLLTEAPLNPKANREKMTQIMFETFNVPAMYVAIQAVLSLYASGRTTGIVLDSG
DGVTHNVPIYEGYALPHAIMRLDLAGRDLTDYLMKILTERGYSFVTTAEREIVRDIKEKLCYVALDFENEMATAASSSSL
EKSYELPDGQVITIGNERFRCPETLFQPSFIGMESAGIHETTYNSIMKCDIDIRKDLYANNVMSGGTTMYPGIADRMQKE
ITALAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWITKQEYDEAGPSIVHRKCF

DEDETTALVCDNGSGLVKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEAQSKRGILTLKYPIEHGIITNWD
DMEKIWHHTFYNELRVAPEEHPTLLTEAPLNPKANREKMTQIMFETFNVPAMYVAIQAVLSLYASGRTTGIVLDSGDGVT
HNVPIYEGYALPHAIMRLDLAGRDLTDYLMKILTERGYSFVTTAEREIVRDIKEKLCYVALDFENEMATAASSSSLEKSY
ELPDGQVITIGNERFRCPETLFQPSFIGMESAGIHETTYNSIMKCDIDIRKDLYANNVMSGGTTMYPGIADRMQKEITAL
APSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWITKQEYDEAGPSIVHRKCF

GGGGGMAPPAPPLPPPLPGSCEFLSPPPPPLPGLGCPPPPPPLLPGMGWGPPPPPPPLLPCTCSPPVAGGMEEVIVAQVD
HGLGSAWVPSHRRVNPPTLRMKKLNWQKLPSNVAREHNSMWASLSSPDAEAVEPDFSSIERLFSFPAAKPKEPTMVAPRA
RKEPKEITFLDAKKSLNLNIFLKQFKCSNEEVAAMIRAGDTTKFDVEVLKQLLKLLPEKHEIENLRAFTEERAKLASADH
FYLLLLAIPCYQLRIECMLLCEGAAAVLDMVRPKAQLVLAACESLLTSRQLPIFCQLILRIGNFLNYGSHTGDADGFKIS
TLLKLTETKSQQNRVTLLHHVLEEAEKSHPDLLQLPRDLEQPSQAAGINLEIIRSEASSNLKKLLETERKVSASVAEVQE
QYTERLQASISAFRALDELFEAIEQKQRELADYLCEDAQQLSLEDTFSTMKAFRDLFLRALKENKDRKEQAAKAERRKQQ
LAEEEARRPRGEDGKPVRKGPGKQEEVCVIDALLADIRKGFQLRKTARGRGDTDGGSKAASMDPPRATEPVATSNPAGDP
VGSTRCPASEPGLDATTASESRGWDLVDAVTPGPQPTLEQLEEGGPRPLERRSSWYVDASDVLTTEDPQCPQPLEGAWPV
TLGDAQALKPLKFSSNQPPAAGSSRQDAKDPTSLLGVLQAEADSTSEGLEDAVHSRGARPPAAGPGGDEDEDEEDTAPES
ALDTSLDKSFSEDAVTDSSGSGTLPRARGRASKGTGKRRKKRPSRSQEGLRPRPKAK

Structure of the formin Cdc12 bound to the barbed end of phalloidin-stabilized F-actin

Reconstruction of the formin Cdc12 bound to the barbed end of phalloidin-stabilized F-actin

Cryo-EM reconstruction of the formin Cdc12 bound to the barbed end of F-actin (without phalloidin)

Structure of the F-actin barbed end bound by Cdc12 and profilin (ring complex) at a resolution of 6.3 Angstrom

Reconstruction of the F-actin barbed end bound by Cdc12 and profilin (ring complex) at a resolution of 6.3 Angstrom

Structure of the undecorated barbed end of F-actin

Reconstruction of the undecorated barbed end of F-actin

Structure of the F-actin barbed end bound by formin mDia1

Reconstruction of the F-actin barbed end bound by formin mDia1

actin, formin, INF2, actin end, barbed end, STRUCTURAL PROTEIN

MAPPAPPLPPPLPGSCEFLPPPPPPLPGLGCPPPPPPLLPGMGWGPPPPPPPLLPCTCSPPVAGGMEEVIVAQVDHGLGS
AWVPSHRRVNPPTLRMKKLNWQKLPSNVAREHNSMWASLSSPDAEAVEPDFSSIERLFSFPAAKPKEPTMVAPRARKEPK
EITFLDAKKSLNLNIFLKQFKCSNEEVAAMIRAGDTTKFDVEVLKQLLKLLPEKHEIENLRAFTEERAKLASADHFYLLL
LAIPCYQLRIECMLLCEGAAAVLDMVRPKAQLVLAACESLLTSRQLPIFCQLILRIGNFLNYGSHTGDADGFKISTLLKL
TETKSQQNRVTLLHHVLEEAEKSHPDLLQLPRDLEQPSQAAGINLEIIRSEASSNLKKLLETERKVSASVAEVQEQYTER
LQASISAFRALDELFEAIEQKQRELADYLCEDAQQLSLEDTFSTMKAFRDLFLRALKENKDRKEQAAKAERRKQQLAEEE
ARRPRGEDGKPVRKGPGKQEEVCVIDALLADIRKGFQLRKTARGRGDTDGGSKAASMDPPRATEPVATSNPAGDPVGSTR
CPASEPGLDATTASESRGWDLVDAVTPGPQPTLEQLEEGGPRPLERRSSWYVDASDVLTTEDPQCPQPLEGAWPVTLGDA
QALKPLKFSSNQPPAAGSSRQDAKDPTSLLGVLQAEADSTSEGLEDAVHSRGARPPAAGPGGDEDEDEEDTAPESALDTS
LDKSFSEDAVTDSSGSGTLPRARGRASKGTGKRRKKRPSRSQEGLRPRPKAK