Catalyzes the attachment of alanine to tRNA(Ala) in a two-step reaction: alanine is first activated by ATP to form Ala- AMP and then transferred to the acceptor end of tRNA(Ala). Also edits incorrectly charged Ser-tRNA(Ala) and Gly-tRNA(Ala) via its editing domain (By similarity). 887 MSGVNEIRSMFLDYFRKNGHEVVPSSPLVPRNDPTLMFTNAGMVQFKNVFTGLEQRPYSTAATAQKCVRAGGKHNDLDNVGYTARHHTFFEMLGNFSFGDYFKERAIELAWNLITKEYGLDAKRLLVTVYHTDDEAFGLWKKIAGLSDDRIIRIATSDNFWAMGDTGPCGPCSEIFYDHGDHIWGGPPGSADEDGDRFIEIWNLVFMQYEQITKEERVDLPRPSIDTGMGLERLAAVLQGQHDNYDIDLFRALIAASEEATGVKAEGDRRASHRVIADHLRSSAFLIADGVLPSNEGRGYVLRRIMRRAMRHAQLLGAQDPLMWKLLPALVGQMGRAYPELVRAEALISETLKLEETRFRKTLERGLNLLEEASADLSEGDQFNGETAFKLYDTYGFPLDLTQDALRAKGIGVDTDAFTAAMQRQKAEARANWTGSGDAATETIWFELRDKHGATDFLGYDTESAEGVIQAIVRDGTVVESASKGETVQLVLNQTPFYGESGGQVGDTGVVTTESGKLTVTDTQKRGEGLFVHYCVVEEGSVKTGEAAALAVDHARRTRLRANHSATHLLHEALREVLGTHVSQKGSLVAPERLRFDVSHPKPMTSEELKVVEEMANEIIVQNTPVVTRLMSVDDAIAEGAMALFGEKYGDEVRVVSMGQGLHGSKAGKAYSVELCGGTHVSATGDIGLVRIVSESAVGSGVRRVEALTGEAARAYLGEQDERVKALAAALKVQPSDVLGRVESLLDERRKLERELTEAKKKLALAGDGQNGSGEAAREIGGVRFLGRVVSGVEPKDLKSLADDGKKTLGSGVVAFVGVSGDGKASAVVAVTDDLTSKVSAVDLVRVASAALGGKGGGGRPDMAQAGGPDGGRAAEAIEAVAVALAG Smed_1521 Alanine--tRNA ligase Alanyl-tRNA synthetase SYA_SINMW alaS