X0306 4 2019-01-17 0 0001373707 TETRAPHASE PHARMACEUTICALS INC TTPH 0001663605 Watt Christopher C/O TETRAPHASE PHARMACEUTICALS, INC. 480 ARSENAL STREET, SUITE 110 WATERTOWN MA 02472 0 1 0 0 SVP, Finance Common Stock 2019-01-06 5 A 0 E 2668 A 21782 D Common Stock 2018-05-14 5 A 0 E 2058 A 23840 D Common Stock 2018-11-14 5 A 0 E 3332 A 27172 D Restricted Stock Units 2019-01-17 4 A 0 80000 0.00 A Common Stock 80000 80000 D On January 6, 2016, the Reporting person was granted 12,500 restricted stock units ("RSUs")( the "2016 RSU grant") that were previously reported on Table II Of Form 4, which form was filed with the Securities and Exchange Commission on March 20, 2018. Of the 2016 RSU grant, 4,166 shares vested on January 6, 2019 of which 1,498 shares were withheld by the Issuer to satisfy the reporting person's tax withholding obligations in connection with the delivery of the conversion of the RSUs into common stock on the vesting date. The total number of shares beneficially owned by the reporting person includes the 2,668 RSUs converted into shares of common stock of the Issuer on the January 2019 vesting date. The RSUs converted into shares of common stock of the Issuer prior to the January 2019 vesting date were previously reported as shares beneficially owned by the reporting person. The amount of securities beneficially owned by the reporting person following the transaction reported on this Form 4 reflects the purchase by the reporting person of 2,058 shares of common stock on May 14, 2018 pursuant to the issuer's 2014 Employee Stock Purchase Plan. The amount of securities beneficially owned by the reporting person following the transaction reported on this Form 4 reflects the purchase by the reporting person of 3,332 shares of common stock on November 14, 2018 pursuant to the issuer's 2014 Employee Stock Purchase Plan. Each restricted stock unit represents a contingent right to receive one share of common stock of Tetraphase Pharmaceuticals, Inc. for no consideration. The restricted stock units vest in three equal installments on each of January 17, 2020, January 17, 2021 and January 17, 2022. /s/Maria Stahl as Attorney-in-Fact for Christopher Watt 2019-01-18